 |
Transcriber's Note:
If the pdf version of the book is viewed using facing pages with even numbered pages on the left, you will see a close approximation of the original book.
Notations of the form "(1,650) 2" appear at the bottom of some pages; they are probably printer's references for assembling to book.
The text only version is of limited use because of the many figures used. I recommend the pdf or rtf versions.
Some of the projects should be approached with care since they involve corrosive or explosive chemicals, electricity and steam boilers.
Do not use lead solder, particularly on cooking utensils.
Whether you simply want to travel back into the mind of a young boy at the beginning of the twentieth century, or want to try your hand at some interesting projects in carpentry, machinery, kites and many other areas, have fun.
The following are definitions of unusual (to me) terms used frequently in the text.
Terms
Batten - Narrow strip of wood.
Bevel (Bevelling) - A cut that is not a right angle.
Bradawl - Awl with a beveled tip to make holes in wood for brads or screws.
Chamfer - Cut off the edge or corner; bevel.
Boss - Enlarged part of a shaft where another shaft is coupled or a wheel or gear is keyed.
Broach - To shape a hole with a tapered tool.
Carbide - Calcium carbide, used to produce acetylene (C2H2) gas for lighting and welding.
Compo - "Composition", like plastic.
Creosote - An oily liquid containing phenols and creosols, obtained from coal tar. Used as a wood preservative and disinfectant. Can cause severe neurological disturbances if inhaled.
Deal - A fir or pine board of standard dimensions
Fish-plate - A plate bolted to the sides of two abutting railroad tracks.
Fretworking - Ornamental design, often in relief.
Gasholder Gasometer - Storage container for fuel gas, especially a large, telescoping, cylindrical tank.
Gland - The outer sleeve of a stuffing box that prevents leakage past a moving machine part.
Glass paper - Paper faced with pulverized glass, like sandpaper.
Gudgeon - A metal pivot or journal at the end of a shaft or an axle, around which a wheel or other device turns.
Joiner - A cabinetmaker.
Linoleum - A floor covering made in sheets by pressing heated linseed oil, rosin, powdered cork, and pigments onto a burlap or canvas backing.
Lissom - Easily bent; supple
Longitudinal - Relating to length.
Mortice - Cavity in a piece of wood or other material, prepared to receive a tenon and form a joint.
Panel saw - Handsaw with fine teeth.
Pinion - Gear with a small number of teeth designed to mesh with a larger gear.
Plinth - Architectural support or base.
Rasp - Coarse file with sharp, raised, pointed projections.
Sleeper - Railroad crosstie.
Spanner - Wrench
Spirit Lamp - Alcohol lamp; see example on page 188.
Spirit - Alcohol
Strake - Ridge of thick planking on the side of a wooden ship.
Strut - Any part designed to hold things apart or resist compressive stress;
Tap - Cut screw threads
Tenon - Projection on the end of a piece of wood shaped for insertion into a mortise to make a joint.
Tenon saw - Saw with a thin blade for cutting tenons.
Tinning - Coating with soft solder.
Turner - Person who operates a lathe or similar device.
Tyre - Tire
Vestas - Matches; Vestai is the Roman goddess of the hearth, worshiped in a temple containing the sacred fire tended by the vestal virgins.
Currency Conversion
Prices are quoted in old English currency, pounds, shillings, pence.
"12s. 6d." is read as "12 Shillings and 6 Pence."
Pence/penny Shilling—12 pence. Crown—5 shillings. Pound—20 shillings. Guinea—21 shillings.
The approximate value of 1900 prices in 2002 is: 1900 Unit Value in 2002 Currency English Pound US Dollars Pence .26 .48 Shilling 3.10 5.80 Crown 15.50 29.00 Pound 62.00 116.00
[End Transcriber's note.]
Photo: Daily Mirror. Large model locomotive built for one of the royal princes of Siam by Messrs. Bassett-Lowke, Limited. It is one-quarter the size of a modern express engine; weighs two tons, with tender; is fifteen feet long; will pull seventy persons; and has a highest speed of about thirty miles an hour.
THINGS TO MAKE BY ARCHIBALD WILLIAMS AUTHOR OF "VICTORIES OF THE ENGINEER," "HOW IT WORKS," "HOW IT IS MADE," ETC., ETC. THOMAS NELSON AND SONS, LTD. LONDON, EDINBURGH, AND NEW YORK
PREFACE.
The making for oneself of toys and other objects of a more or less useful character has certain advantages over buying them. In the case of the more elaborate and costly articles, it may enable one to possess things which otherwise would be unobtainable. Secondly, a home-made article may give a satisfaction more lasting than is conferred by a bought one, though it may be less beautiful to look upon. Thirdly, the mere making should be a pleasure, and must be an education in itself.
To encourage readers to "use their hands" the following chapters have been written. The subjects chosen provide ample scope for the exercise of ingenuity and patience; but in making my selection I have kept before me the fact that a well-equipped workshop falls to the lot of but a few of the boys who are anxious to develop into amateur craftsmen. Therefore, while the easiest tasks set herein are very easy, the most difficult will not be found to demand a very high degree of skill, or more than a very moderate outlay on tools. I may say here that I have been over the ground myself to find out its difficulties for my readers, and that I made an engine similar to that described in Chapter XV (the most elaborate mechanism included in the book) with very simple tools. Some of the items which I had on my original list were abandoned, because they presupposed the possession of comparatively expensive machines.
My selection has also been guided by the desire to cater for different tastes. In some cases the actual manufacture of the thing described may be regarded as the most instructive and valuable element, and may appeal most forcibly to the "handy" boy; in others—the Harmonograph provides a good instance—the interest centres round the experiments made possible by the construction of a simple piece of apparatus; in some the utility of the article manufactured is its chief recommendation.
I feel certain that anyone who follows out the pages of this volume with hand as well as with eye, will have little reason to regret the time so spent. The things made may in course of time be put aside and forgotten, but the manual skill acquired will remain. Nowadays one can buy almost anything ready-made, or get it made without difficulty; yet he who is able to make things for himself will always have an advantage over the person to whom the use of tools is an unprobed mystery.
CONTENTS.
I. SAWING TRESTLE II. A JOINER'S BENCH III. A HANDY BOOKSTAND IV. A HOUSE LADDER V. A DEVELOPING SINK VI. A POULTRY HOUSE AND RUN VII. A SHED FOR YOUR BICYCLE VIII. A TARGET APPARATUS FOR RIFLE SHOOTING IX. CABINET-MAKING X. TELEGRAPHIC APPARATUS XI. A RECIPROCATING ELECTRIC MOTOR XII. AN ELECTRIC ALARM CLOCK XIII. A MODEL ELECTRIC RAILWAY XIV. A SIMPLE RECIPROCATING ENGINE XV. A HORIZONTAL SLIDE-VALVE ENGINE XVI. MODEL STEAM TURBINES XVII. STEAM TOPS XVIII. MODEL BOILERS XIX. QUICK-BOILING KETTLES XX. A HOT-AIR ENGINE XXI. A WATER MOTOR XXII. MODEL PUMPS XXIII. KITES XXIV. PAPER GLIDERS XXV. A SELF-LAUNCHING MODEL AEROPLANE XXVI. APPARATUS FOR SIMPLE SCIENTIFIC EXPERIMENTS XXVII. A RAIN GAUGE XXVIII. WIND VANES WITH DIALS XXIX. A STRENGTH-TESTING MACHINE XXX. LUNG-TESTING APPARATUS XXXI. HOME-MADE HARMONOGRAPHS XXXII. A SELF-SUPPLYING MATCHBOX XXXIII. A WOODEN WORKBOX XXXIV. WRESTLING PUPPETS XXXV. DOUBLE BELLOWS XXXVI. A HOME-MADE PANTOGRAPH XXXVII. A SILHOUETTE DRAWING MACHINE XXXVIII. A SIGNALLING LAMP XXXIX. A MINIATURE GASWORKS
THINGS TO MAKE.
I. A SAWING TRESTLE
A strong and stable sawing trestle is one of the most important accessories of the carpenter's shop, whether amateur or professional. The saw is constantly being used, and for it to do its work accurately the material must be properly supported, so that it cannot sway or shift. Anybody who has been in the habit of using a wobbly chair or box to saw on will be surprised to find how much more easily wood can be cut when resting on a trestle like that illustrated by Figs. 1 to 3.
The top, a, of the trestle is 29 inches long, 4 inches wide, and 2 inches thick. At one end it has a deep nick, to serve much the same purpose as the notched board used in fretworking; also to hold on edge such things as doors while their edges are planed up. Pushed back against the wall the trestle is then "as good as a boy."
The four legs are made of 2 by 2 inch stuff. To start with, the pieces should be 24 inches long, to allow for the waste of cutting on the angle.
Cutting the Notches.—Make four marks 7 inches from the four corners of the top, set your bevel to an angle of 70 degrees (or cut an angle out of a card with the help of a protractor), and lay a leg against each mark in turn, the end projecting an inch or so above the top. Move the leg about till it makes the proper angle at the mark, and draw a pencil line down each side of the leg as close up as possible. Since the legs may vary slightly in size, use each once only for marking, and number it and the place to which it belongs.
Lines must now be drawn along the upper and under sides of the top, parallel to and 3/4-inch from the edge, to complete the marking out of the notches.
Cut just inside the side marks with a fine tenon saw, and remove the wood between the cuts back to the top and bottom marks with a broad, sharp chisel, making the surface of the cut as true and flat as you can. Then "offer" the leg that belongs to the cut, its end projecting an inch or so. If it won't enter, bevel off the sides of the cut very slightly till it will. A good driving fit is what one should aim at. While the leg is in place, draw your pencil in the angles which it makes with the top above and below, to obtain the lines AB, CD (Fig. 2, a).
Bevelling the Legs.-The marking out of the bevels will be much expedited if a template is cut out of tin or card. It should be just as wide as the legs, and at a point 4 inches from one end run off at an angle of 162 degrees from one edge. (See Fig. 2,b.)
Draw with a square a line, EEl, across what is to be the inside of the leg. The template is applied to the end side of the leg and moved up till its sloping edge occupies a position in which a perpendicular dropped on to it from C is 1/2 inch long. Mark the line EF (Fig. 2, b) and the perpendicular CG. The bevel is marked on the other side of the leg, the, angle of the template being at E1 (Fig. 2, a) to guide the saw, which is passed down through the leg just outside the marks till in line with CD. The piece is detached by a cross cut along CG, CD. This procedure, which sounds very complicated, but is really very simple, and performed much more quickly than it can be described, yields a leg properly bevelled and provided with a shoulder to take the weight of the top.
The leg at the diagonally opposite corner is an exact replica of the one first made; the other two are similar, but the direction of the bevels is reversed, as will be evident after a little consideration.
When all the legs are ready, knock them into place, driving the shoulders tight up against the top, and nail them on. The projections are sawn off roughly and planed down flush with the top. Then affix the tie C at each end, and plane its edges off neatly.
Truing the Legs.—Stand the stool on end, top flat against the wall. Measure off a 20-inch perpendicular from the wall to the outside corner of each of the two upper legs. (Fig. 3.) Lay a straightedge from mark to mark, and draw lines across the legs. Reverse the trestle, and do the same with the legs at the other end. Then turn the trestle on its side, and draw lines on the other outside faces of the legs, using the lines already made as guides. If the operation has been carried through accurately, all eight lines will be in a plane parallel to the top. Cut off the ends of the legs below the lines, and the trestle is finished.
II. A JOINER'S BENCH.
After finishing his sawing trestle the reader may be willing to undertake a larger job, the manufacture of a joiner's bench—if he does not already possess a good article—heavy and rigid enough to stand firm under plane and hammer.
For the general design and detailed measurements he is referred to Figs. 4 and 5, in which the dimensions of each part are figured clearly. The length of 5 feet, width of 2 feet (exclusive of the back E), and height of 2 feet 7-1/2 inches will be found a good average. If the legs prove a bit long for some readers, it is a simple matter to lay a plank beside the bench to raise the (human) feet an inch or two.
In order to give rigidity, the struts S1S2 of the trestles at the end and the braces DD on the front are "halved" where they overlap the legs and front so as to offer the resistance of a "shoulder" to any thrust.
Materials.—The cost of these will be, approximately: wood, 12s. 6d.; [12 Shillings. 6 Pence] bench screw, 1s. 6d.; nails and screws, 1s.; or 15s. in all. It is advisable to show the timber merchant the specifications, so that he may cut up the stuff most economically.
If the wood is mill-planed before delivery a lot of trouble will be saved, as no further finish will be required, except perhaps at the top corners. In passing, one should remark that the boards used should be of the widths and lengths given; while as regards thickness the figures must be taken as nominal, as in practice the saw cut is included. Thus a 1-inch board would, when planed, be only 7/8 to 15/16 inch thick, unless the actual size is specified, in which case something extra might be charged.
Construction.
The Trestles.—These should be made first. Begin by getting all the legs of exactly the same length, and square top and bottom. Then cut off two 22-inch lengths of the 6 by 1 inch wood, squaring the ends carefully. Two of the legs are laid on the floor, one end against the wall or a batten nailed to the floor and arranged parallel to one another, as gauged by the piece C, which is nailed on perfectly square to both, and with its top edge exactly flush with the ends of the legs.
Next take the 3 by 1 inch wood for the struts, and cut off a piece 32 inches long. Two inches from one end of it make a cross mark with the square, and from the ends of the mark run lines towards the end at an angle of 45 degrees. Cut along these lines, and lay one of the edges just cut up against C, and flush with the outer edge of L1 (Fig. 5). Tack the strut on temporarily to both legs, turn the trestle over, and draw your pencil (which should have a sharp point) along the angles which the strut makes with the legs. This gives you the limits of the overlaps. Detach the strut.
The marking-gauge now comes into use. Set it at 3/8 inch, and make marks on the sides of the strut down to the limits, pressing the guide against what will be the inner face of the board. The ends must now be divided down along the gauge scratches to the limit mark with a tenon or panel saw, the saw being kept on the inside of the mark, So that its cut is included in the 3/8 inch, and a cross cut made to detach the piece and leave a shoulder. The strut is "offered" again to the legs, and a mark is drawn across the bottom parallel to the ends or the legs for the final saw cut. Nail on the strut, pressing the legs well up against the shoulders. Its fellow on the other side of the legs is prepared in exactly the same manner; and the second trestle is a duplicate of the first, with the exception that the directions of the struts are reversed relatively to the C piece, to preserve the symmetry—which, however, is not an important point.
Back and Front.—The only operation to be performed on the front piece B and the back G is the notching of them both on the inside faces at the centre to take the ends of the bearer F, which performs the important function of preventing any bending of the top planks. Lay the boards together, top edges and ends level, and mark them at the same time. The square is then used on the faces to give the limits for the notches, which should be 1/4 inch deep and chiselled out carefully.
Draw cross lines with your square 3 inches from each end of both pieces, on the inside, to show where the legs are to be. Bore holes in the boards for the 3-inch screws which will hold them to the legs.
Attaching the Trestles.—Stand the trestles on their heads and lay the back and front up to them, using the guide marks just drawn. A nail driven part way in through one of the screw holes, and a batten tacked diagonally on the DD lines, will hold a leg in position while the screws are inserted. (Make sure that the tops of the legs and the top edges of B and G are in the same plane.)
Affixing the Braces.—The braces DD, of 3 by 1 inch stuff, can now be marked off and cut exactly down the middle to the limits of the overlap. Screw on the braces.
The bearer F is next cut out. Its length should be such as to maintain the exact parallelism of B with G, and the ends be as square as you can cut them. Fix it in position by two 2-inch screws at each end.
The bench is now ready for covering. Begin with the front board, A1. Bore countersunk holes for 3-inch screws over the centre of the legs and half an inch from the front edge, 1 foot apart. Arrange Al with its front edge perfectly flush with the face of B, and tack it in place by nails driven through a couple of screw holes, and insert all the screws. The middle board, A2, is laid up against it, and the back board, A3 (bored for screws like the front board), against that. Screw down A3.
You must now measure carefully to establish lines over the centres of CC and F. Attach each board to each of these by a couple of screws. All screws in the top of the bench are countersunk 1/8 inch below the surface. Screw the ledge E, of 4 by 5/8 inch wood, on to the back of G, with 2-1/2 inches projecting. This will prevent tools, etc., slipping off the bench.
The Vice.—This important accessory consists of an 8 by 2 by 15 inch piece, V, a 2-inch diameter wooden bench screw and threaded block, and a guide, F. (Note.—A 1-1/8-inch diameter wrought iron screw is very preferable to the wooden, but its cost is about 4s. more.) V should be tacked to B while the 2-inch hole for the bench screw is bored through both with a centre bit, at a point 8 inches from the guide end on the centre line of V. This hole must be made quite squarely to enable the screw to work freely. If a 2-inch bit is not available, mark out a 2-inch ring and bore a number of small holes, which can afterwards be joined by a pad-saw; and finish, the hole thus formed with a half-round rasp. The threaded block for the screw is attached to the inner side of H in the angle formed by the leg and the board A1. The guide F is then fitted. This is pinned in to V, and the slides through B. If a rectangular piece is used, cut the hole in V first; then screw V up tightly, and mark B through V. It may be found more convenient to use a circular piece, in which case the holes for it can be centre-bitted through V and B in one operation. If after fitting V projects above A, plane it down level.
The finishing touches are rounding off all corners which might catch and fray the clothes, and boring the 3/4-inch holes, HH, for pegs on which planks can be rested for edge planing.
For a "stop" to prevent boards slipping when being planed on the flat, one may use an ordinary 2-inch wood screw, the projection of which must of course be less than the thickness of the board planed. Many carpenters employ this very simple expedient; others, again, prefer a square piece of wood sliding stiffly through a hole in A1 and provided on top with a fragment of old saw blade having its teeth projecting beyond the side facing the work. The bench is countersunk to allow the teeth to be driven down out of the way when a "clear bench" is required.
Just a word of warning in conclusion. Don't be tempted to nail the parts together—with the exception of the trestle components—to save trouble. The use of screws entails very little extra bother, and gives you a bench which can be taken to pieces very quickly for transport, and is therefore more valuable than a nailed one.
III. A HANDY BOOKSTAND.
A bookstand of the kind shown in Fig. 7 has two great advantages: first, it holds the books in such a position that their titles are read more easily than when the books stand vertically; second, it can be taken to pieces for packing in a few moments, as it consists of but four pieces held together by eight removable wedges. We recommend it for use on the study table.
Oak or walnut should preferably be chosen as material, or, if the maker wishes to economize, American whitewood or yellow pine. Stuff 1/4 inch (actual) thick will serve throughout if the stronger woods are used; 3/8 inch for the shelf parts in the case of whitewood or pine.
The ends (Fig. 8) are sawn out of pieces 5-1/2 by 10 inches, and nicely rounded off on all but the bottom edge, which is planed flat and true. The positions for the holes through which the shelf eyes will project must be marked accurately, to prevent the stand showing a twist when put together. The simplest method of getting the marks right is to cut a template out of thin card and apply it to the two ends in turn, using the base of each as the adjusting line. Fret-saw the holes, cutting just inside the lines to allow for truing up with a coarse file.
The shelves a and b are 15 inches long, exclusive of the lugs c, c, c, c, and 4-1/2 and 4-3/4 inches wide respectively. As will be seen from Fig. 8, b overlaps a. Both have their top edges rounded off to prevent injury to book bindings, but their bottom edges are left square.
As the neatness of the stand will depend largely on a and b fitting closely against the sides, their ends should be cut out and trued carefully, special attention being paid to keeping the shoulders between and outside the lugs in a straight line. The wedge holes in c, c, c, c measure 1/2 by 1/4 inch, and are arranged to be partly covered by the sides, so that the wedges cannot touch their inner ends. (See Fig. 9.) This ensures the shelves being tightly drawn up against the sides when the wedges are driven home.
The wedges should be cut on a very slight taper of not more than half an inch in the foot run, in order to keep their grip. Prepare a strip as thick as the smaller dimension of the holes, 3/8 inch wide at one end, and 7/8 inch wide at the other. Assemble the parts and push the piece through a hole until it gets a good hold, mark it across half an inch above the hole, and cut it off. Then plane the strip down parallel to the edge that follows the grain until the end will project half an inch beyond the lug next fitted. Mark and cut off as before, and repeat the process until the eight wedges are ready in the rough. Then bevel off the outside corners and smooth them—as well as the rest of the woodwork—with fine glass paper.
Shelves and sides should be wax-polished or given a coat or two of varnish.
Don't drive the wedges in too tight, or yon may have to lament a split lug.
If the stand is to be used for very heavy books, or the shelves are much longer than specified here, it is advisable to bring the angle of the shelves down to the bottom of the standards, to relieve the shelves of bending strain at the centre; or to use stouter material; or to unite the shelves at two or three points by thin brass screws inserted through holes drilled in the overlapping part.
IV. A HOUSE LADDER.
The preparation and putting together of the parts of a ladder having round, tapered rungs let into holes in the two sides is beyond the capacity of the average young amateur; but little skill is needed to manufacture a very fairly efficient substitute for the professionally-built article—to wit, a ladder of the kind to which builders apply the somewhat disparaging adjective "duck."
The rungs of such a "duck" ladder are merely nailed to the outside if the ladder is required for temporary purposes only; but as we are of course aiming at the construction of a thing made to last, we shall go to the trouble of "notching-in" each rung (see Fig. 10), so that the sides shall take the weight directly, and the nails only have to keep the rungs firmly in position. The objection to notching-in is that it reduces the strength of the ladder, which is of course only that of the wood between the bottom of the notches and the plain side. Therefore it is necessary to have sides somewhat deeper than would be required for a centrally-runged ladder; which is pierced where the wood is subjected to little tension or compression.
Materials.—The length of the ladder will decide what the stoutness of the sides should be. For a ladder about 12 feet long, such as we propose to describe, larch battens 3 by 1-1/8 inches (actual) in section and free from knots, especially at the edges, will be sufficiently strong to carry all reasonable weights without danger of collapse. But be sure to get the best wood obtainable. The rungs may be of 2 by 1 inch stuff, though 2 by 3/4 inch will suffice for the upper half-dozen, which have less wear, and are shorter than those below.
The rungs are 10 inches apart (Fig. 10), centre to centre. The distance may be increased to a foot, Or even more if weight-saving is an object.
CONSTRUCTION.
Preparing the Sides.—These are cut to exactly the same length, which we will assume to be 11 feet 6 inches, planed quite smooth and rounded off slightly at the corners to make handling comfortable. Before marking them for the rungs it is important that they shall be so arranged that both incline equally towards a centre line.
Stretch a string tightly three inches above the ground, and lay the sides of the ladder on edge to right and left of it, their ends level. Adjust the bottom ends 8-1/2, the top ends 6-1/2 inches from the string, measuring from the outside. Tack on cross pieces to prevent shifting, and then, starting from the bottom, make a mark every 10 inches on the outside corners, to show the position of the tops of the rungs. A piece of the wood to be used for making the rungs of is laid up to the pairs of marks in turn, and lines are drawn on both sides of it.
Cutting the Notches.—The work of marking the ends of the notches will be quickened, and rendered more accurate, if a template (Fig. 10) is cut out of tin. The side AC is 3/8 to 1/2 inch deep. Apply the template to both faces of the side in turn, with its corner A at the line below the rung, and DE flush with the upper corner. When all the notches have been marked cut down the AC line of each with a tenon saw, and chisel along BC till the wedge-shaped chip is removed. Finish off every notch as neatly as possible, so that the rungs may make close contact and keep water out.
Preparing the Rungs.—Lay a piece of rung batten across the lowest notches, the end overhanging the side by a quarter of an inch or so to allow for the taper of the ladder, and draw your pencil along the angles which it makes with the sides. Mark the positions of the nail holes. Cut off the rung at the cross lines; drill the four nail holes on the skew, as shown in Fig. 10; and round off all the corners. The other rungs are treated in the same manner, and the sides are then separated, for the inside top corner and both back corners, which will be handled most, to be well rounded off and rubbed smooth with glass paper.
Assembling.—Before putting the parts together give them a coating of paint, as the contact surfaces will not be accessible to the brush afterwards. When the paint has dried, lay the sides out as before, and nail on the rungs with 3-inch nails. To counteract any tendency of the sides to draw apart, a light cross bar should be fixed on the back of the ladder behind the top and bottom rungs.
Round off the end angles of the rungs, and apply a second coating of paint.
Note.—A ladder of this kind is given a more presentable appearance if the rungs are let in square to the sides and flush, but at the sacrifice either of strength or lightness, unless narrow rungs of a hard wood, such as oak, be used. Moreover, square notches are not so easy to cut out as triangular.
For a short ladder, not more than 9 feet long, the section of the sides may safely be reduced to 2-3/4 by 1 inch (actual), if good material is selected.
V. A DEVELOPING SINK.
Many amateur photographers are obliged to do their developing in odd corners and under conditions which render the hobby somewhat irksome if a large number of plates have to be treated. The main difficulty is to secure an adequate water supply and to dispose of the waste water. At a small expenditure of money and energy it is easy, however, to rig up a contrivance which, if it does not afford the conveniences of a properly equipped dark room, is in advance of the jug-and-basin arrangement with which one might otherwise have to be content. A strong point in favour of the subject of this chapter is that it can be moved without any trouble if the photographer has to change his quarters.
The foundation, so to speak, of the developing sink is a common wooden washstand of the kind which has a circular hole in the top to hold the basin. A secondhand article of this sort can be purchased for a shilling or two. A thoroughly sound specimen should be selected, even if it is not the cheapest offered, especial attention being paid to its general rigidity and the good condition of the boards surrounding the basin shelf.
The area of the top is generally about 20 by 15 inches; but if a stand of larger dimensions can be found, choose it by preference.
The general design of the sink and its equipment is shown in Fig. 11. For the uprights, which rest on the beading of the washstand, use two boards 9 inches wide, 1/2 inch (actual) thick, and 36 inches long. The top shelf, to carry the pail or other water container, should be of 1-inch stuff; and the two lower shelves be not more than 5 inches wide and 3/4 inch thick. Space the shelves at least 11 inches apart, so that they may accommodate tall bottles. The superstructure will gain in rigidity if the intermediate shelves are screwed to the uprights, in addition to being supported on ledges as indicated; and if the back is boarded over for at least half its height, there will be no danger of sideways collapse, when a full bucket is put in position.
The top of the washstand, on which the developing will be done, must be provided with a tray of lead or zinc. Lead is preferable, as lying flatter; but the jointing at the corners is more difficult than the soldering of sheet zinc, which, though more liable to chemical corrosion, is much lighter than the thinnest lead—weighing about 1-1/2 lbs. to the square foot—that could well be used. If lead is selected, the services of a plumber had better be secured, if the reader has had no experience in "wiping a joint."
A zinc tray is prepared by cutting out of a single sheet a piece of the shape shown in Fig. 12. The dimensions between the bending lines (dotted) are 1/8 inch less in both directions than those of the shelf. The turn-ups a, a, b, b, should not be less than 1-1/2 inches wide. Allow half an inch at each end of b b for the turnover c. Turn a a up first, then b b, and finally bend c c round the back of a a, to which they are soldered. A drop of solder will be needed in each corner to make it water-tight. When turning up a side use a piece of square-cornered metal or wood as mould, and make the angles as clean as possible, especially near the joints.
A drain hole, an inch or so in diameter, is cut in the centre of the tray. To prevent the hands being injured by the tray, the front should be covered by a 1/2-inch strip of zinc doubled lengthwise, or be made a bit deeper than 1-1/2 inches in the first instance and turned over on itself.
Before the tray is put in position the basin hole must be filled in, except for an opening to take the waste pipe. The plug is pad-sawed out of wood of the same thickness as the top, to which it is attached by crossbars on the under side. The whole of the woodwork, or at least those parts which are most likely to get wetted, should then be given a coat or two of paint.
A waste pipe, somewhat larger than the drain hole and 3 inches long, having been firmly soldered to the tray, beat the edges of the hole down into the pipe. Then prepare a wooden collar to fit the pipe outside, and drill a hole on the centre line to take a carpenter's screw. If the edges of the tray are supported on slats 3/16 to 1/4 inch thick, and its centre is kept in contact with the wood by the collar pressing against the underside of the shelf, any water will naturally gravitate to the centre and escape by the waste pipe. This automatic clearance of "slops" is a very desirable feature of a developing sink.
To prevent water splashing on to the sides of the stand and working down between tray and wood, tack pieces of American cloth on the sides with their edges overlapping the tray edges by an inch or so.
A small two-handled bath is the most convenient receptacle for the waste water. It should hold at least a quarter as much again as the water tank, so as to avoid any danger of overfilling. A piece of old cycle tyre tubing, tied to the waste pipe and long enough to reach below the edge of the bath, will prevent splashing—which, when chemicals are being poured away, might prove disastrous to light-coloured clothes.
The supply pipe has a siphon-piece of "compo" tubing at the top, to draw off the water when the tube has been filled by suction, and a small tap at the bottom. This tap, when not in use, should be held back out of the way by a wire hook attached to the lowest of the upper shelves. A piece of linoleum should be cut to fit the bath-shelf and protect the drawer below.
VI. A POULTRY HOUSE AND RUN.
This chapter should be of interest to the keeper of poultry on a small scale, for even if the instructions given are not followed out quite as they stand, they may suggest modifications to suit the taste and means of the reader.
The principle of the combined run and house—which will accommodate a dozen fowls without overcrowding, especially if it be moved from time to time on to fresh ground—will be understood from Figs. 13 and 14. The first of these shows the framework to which the boards for the house and the wire for the run are nailed. Its over-all length of 10 feet is subdivided into five "bays" or panels, 2 feet long (nearly) between centres of rafters. Two bays are devoted to the house, three to the run.
One square (10 by 10 feet) of weather boarding 6 inches wide, for covering in the house. 44 feet of 4 by 1, for base and ridge. 56 feet of 3 by 1, for eight rafters. 28 feet of 3 by 1-1/2, for four rafters. 50 feet of 2 by 1-1/2, for door frames and doors. 6 feet of 2 by 2, for tie t. 45 feet of 2-foot wire netting. Two pairs of hinges; two locks; staples, etc.
The materials used comprise:— The total cost as estimated from prices current at the time of writing is 25s. This cost could be considerably reduced by using lighter stuff all through for the framework and doors and by covering in the house with old boards, which may be picked up cheaply if one is lucky. Whether it is advisable to sacrifice durability and rigidity to cost must be left to the maker to decide. Anyhow, if the specifications given are followed, an outfit warranted to last for several years will be produced.
A Few Points.—The vertical height of the run is just under 6 feet, the tips being cut away from the rafters at the apex. The width at the ground is exactly 6 feet. The base angles made by AA with B (Fig. 14) are 63 degrees; that which they make with one another, 54 degrees. The rafters r1 and r3 at each end of the house are half an inch thicker than the rest, as they have to stand a lot of nailing.
CONSTRUCTION.
Cutting the Rafters.—If floor space is available, chalk out accurately the external outline of a pair of rafters (80 inches long each before shaping) and a line joining their lower ends. Then draw a line bisecting the ridge angle. With this template as guide the rafters can be quickly cut to shape. Another method is to cut one rafter out very carefully, making a notch for half the width of the ridge, and to use it as a pattern for the rest. In any case the chalked lines will prove useful in the next operation of pairing the rafters and uniting them by a tie just under the ridge notch. Cut a 4 by 1 inch notch at the bottom of each rafter, on the outside, for the base piece. The two end pairs have the B pieces (Fig. 14) nailed on to them, and r3 the tie t, which should be in line with the rafters. The other three pairs require temporary ties halfway up to prevent straddling during erection.
Door Frames and Doors.—The method of fixing the frame of the door at the run end is shown in Fig. 14. The material for the frame being 1/2 inch thicker than that of the rafters, there is room for shoulders at the top angles, as indicated by dotted lines. The door frame at the house end is of the same thickness as r1 so that no overlapping is possible. This being the case, screws should be used in preference to nails, which are liable to draw a sloping face out of position as they get home.
The doors are made of 2 by 2 inch stuff, halved at the corners. Cut out the top and bottom of the two sides; lay them on the floor so as to form a perfect rectangle, and nail them together. The strut is then prepared, care being taken to get a good fit, as any shortness of strut will sooner or later mean sagging of the door. Cut the angles as squarely as possible, to ensure the strut being of the same length both inside and out.
Note.—As the door is rectangular, it does not matter which corners are occupied by the ends of the strut; but when the door is hung, the strut must run relatively to the side on which the hinges are, as shown in Fig. 14. Amateurs—even some professionals—have been known to get the strut the wrong way up, and so render it practically useless.
Covering the Ends of the House.—The ends of the house should be covered before erection, while it is still possible to do the nailing on the flat. The run end is boarded right over, beginning at the bottom, and allowing each board to overlap that below it by 1 inch. The board ends are flush with the outer sides of the rafters. When boarding is finished, cut (with a pad saw) a semicircular-topped run hole, 14 inches high and 8 inches wide, in the middle of the bottom. Any structural weakness caused by severing the two lowest boards is counteracted by the two grooved pieces in which the drop-door moves.
Odds and ends of weather boards should be kept for the door end of the house, which requires short pieces only, and is not boarded below the top of b2. The door may be weather-boarded to match the rest of the end, or covered by a few strakes of match-boarding put on vertically.
The two base pieces, b1 and b2, and the ridge should be marked off for the rafters at the same time. All three are 10-foot lengths of 4 by 1 wood, unless you prefer the ridge to project a bit, in which case you must allow accordingly.
Stand all three pieces together on edge, and make the marks with a square across the tops. Allow a distance of 4 feet between the outside faces of r1 and r3; halve this distance to get the centre of r2; and subdivide the distance between r3 and r6 so that each rafter is separated from its neighbours by an equal space, which will be 1 foot 11 inches. Number the marks and continue them down the sides of the boards with the square. There should be a mark on each side of the place to be occupied by the intermediate rafters, to prevent mistakes; for it is obvious that if a rafter is fixed on the left side of a single ridge mark and on the right of the corresponding mark on the base, the result will not be pleasing.
Erection.—The services of a second pair of hands are needed here, to hold while nailing is done. Nail holes having been drilled in the tops of the rafters and in the base pieces, the ends are stood upright and tacked to the ridge at the places marked for them, and after them the intermediate rafters, working from one end to the other. Then tack on the base pieces, b1, b3. Get the ends quite perpendicular, and nail a temporary cross strut or two on the outside of the rafters to prevent shifting while the final nailing up is done.
Covering the Shed.—Sixteen boards, 4 feet 2 inches long, are needed for each side, as, owing to the overlap of one inch, each tier covers only five of the 80 inches. The ridge is made watertight by a strip of sheet zinc, a foot wide, bent over the top and nailed along each edge.
Waterproofing.—All the woodwork should now be given a coating of well-boiled tar, paint, creosote, or some other preservative, worked well down into the cracks. Creosote and stoprot are most convenient to use, as they dry quickly.
Netting.—When the preservative has dried, fix on the netting with 3/4-inch wire staples. Begin at the base on one side, strain the netting over the ridge, and down to the base on the other side. Be careful not to draw the rafters out of line sideways. The last edge stapled should be that on the roof of the house.
Note.—When driving nails or staples into a rafter or other part, get a helper to hold up some object considerably heavier than the hammer on the farther side to deaden the blow. Lack of such support may cause damage, besides making the work much more tedious and difficult.
Finishing off.—The doors are now hung, and fitted with buttons and padlocks. The stops should be on the doors, not on the frames, where they would prove an obstruction in a somewhat narrow opening. Perches should be of 2 by 1 inch wood, rounded off at the top, and supported in sockets at each end so as to be removable for cleaning; and be all on the same level, to avoid fighting for the "upper seats" among the fowls. A loose floor, made in two pieces for convenience of moving, will help to keep the fowls warm and make cleaning easier, but will add a few shillings to the cost. The inside of the house should be well whitewashed before fowls are admitted. To prevent draughts the triangular spaces between the roof boards and rafters should be plugged, but ample ventilation must be provided for by holes bored in the ends of the house at several elevations, the lowest 2 feet above the base. Handles for lifting may be screwed to the faces of b and b2 halfway between the door frame and the corners.
VII. A SHED FOR YOUR BICYCLE.
The problem, how to house one or more cycles, often gives trouble to the occupiers of small premises. The hall-way, which in many cases has to serve as stable, is sadly obstructed by the handles of a machine; and if one is kept there, the reason generally is that no other storage is available.
If accommodation is needed permanently for two or three cycles belonging to the house, and occasionally for the machine of a visitor, and if room is obtainable in a backyard or garden in direct communication with the road, the question of constructing a really durable and practical cycle shed is well worth consideration. I say constructing, because, in the first place, a bought shed costing the same money would probably not be of such good quality as a home-made one; and secondly, because the actual construction, while not offering any serious difficulty, will afford a useful lesson in carpentry.
Cycle sheds are of many kinds, but owing to the limitations of space it is necessary to confine attention to one particular design, which specifies a shed composed of sections quickly put together or taken apart—portability being an important feature of "tenants' fixtures"—and enables fullest advantage to be taken of the storage room. As will be seen from the scale drawings illustrating this chapter, the doors extend right across the front, and when they are open the whole of the interior is easily accessible. The fact that the cycles can be put in sideways is a great convenience, as the standing of the machines head to tail alternately economizes room considerably.
I ought to mention before going further that the shed to be described is very similar, as regards design and dimensions, to one in a back issue of Cycling. By the courtesy of the proprietors of the journal I have been permitted to adapt the description there given.[1]
[Footnote 1: By Mr. Hubert Burgess. ]
Dimensions and General Arrangements.—The shed is 8 feet long over all, 5 feet 6 inches high in front, 5 feet high at the back, 3 feet deep over all, under the roof, which projects 3 inches fore and aft, and 2 inches at each end. It consists of seven parts: two sides, roof, back, front frame and doors, and a bottom in two sections.
The reader should examine the diagrams (Figs. 16 to 24) to get a clear understanding of the disposal of the parts at the corners. Fig. 16 makes it plain that the frames of the back and front overlap the frames of the sides, to which they are bolted; and that the covering of the back overlaps the covering of the sides, which in turn overlaps the front frame.
All corner joints are halved. In order to allow the doors to lie flush with the front of the doorframe uprights, the last must project the thickness of the door boards beyond the frame longitudinals; and to bring the front uprights of the sides up against the uprights of the door frame, the longitudinals are notched, as shown (Fig. 16), to the depth of the set-back for the doors.
Materials.—The question of cost and the question of materials cannot be separated. A shed even of the dimensions given consumes a lot of wood, and the last, that it may withstand our variable and treacherous climate for a good number of years, should, as regards those parts directly exposed to the weather, be of good quality. Yellow deal may be selected for the boards; pitch pine is better, but it costs considerably more. For the frames and non-exposed parts generally ordinary white deal will suffice.
The scale drawings are based on the assumption that matching of one of the forms shown in Fig. 17, and measuring 4 inches (actual) across, exclusive of the tongue, and 5/8 inch (actual) thick, is used.
As advised in the case of the carpenter's bench, (p. 15) the prospective constructor should let the wood merchant have the specifications, so that he may provide the material in the most economical lengths. The following is a rough estimate of the wood required, allowing a sufficient margin for waste:
4-1/2 (over tongue) by 5/8 inch (actual) yellow match boarding for sides, roof, back, and doors:
1-1/2 squares = 150 sq. feet. = 450 feet run. White 4-1/2 by 3/4 inch square-shouldered flooring: 1/4 square = 25 sq. feet. = 75 feet run. 3 by 1-1/2 inch battens = 88 feet run. 4 by 1-1/2 inch battens = 26 feet run. 3 by 2 inch battens = 27 feet run. 5 by 1-1/2 inch battens = 8 feet run. 2 by 1-1/2 inch battens = 21 feet run.
There will also be required: Twelve 6-inch bolts and nuts. Two pairs 18-inch cross-garnet hinges. Two door bolts. One lock (a good one). Four yards of roofing felt. Two gallons of stoprot. Three lbs. wire-nails A few dozen 3-inch and I-1/2-inch screws.
The total cost of the materials will come to about 2 pounds, 2s.
CONSTRUCTION.
The scale drawings are so complete as to dimensions that, assuming the materials to be of the sizes specified, they may be followed implicitly. It is, of course, easy to modify the design to suit any slight differences in dimensions; and to avoid mistakes all the stuff should be gauged carefully beforehand.
The Sides.—When laying out the frames for these it is necessary to bear in mind that the front upright is somewhat less than 5 feet 6 inches long, and the back upright rather more than 5 feet, owing to the slope of the roof, and to the fact that they are set in 2 inches from the back and front. To get the lengths and angle of the half-joints right, lay the verticals, which should be 5 feet 6 inches and 5 feet 1 inch long before trimming, on the floor, at right angles to the bottom of the frame (2 feet 7-3/4 inches long) and quite parallel to one another. (We will assume the half-joints to have been made at the bottom.) The batten for the top is laid across the ends of the verticals, its top edge in line with a 5-foot 6-inch mark at a point 2 inches beyond the front vertical, and with a 5-foot mark 2 inches beyond the back vertical, the distances being measured perpendicularly from the bottom of the frames produced. The lines for the joints can then be marked, and the joints cut. The notches for the roof stays should not be cut till the roof is being fitted.
Use the side frame first made as template for the other.
The shelves are notched at the ends, so that their back faces shall be flush with the board side of the frame.
Fix the corners with the screws, and plane off the projecting angles of the uprights.
When putting on the boards, start at the back of the frame. Plane down the groove edge of the first board until the groove is out of the board, and apply the board with 1-1/2 inches projecting beyond the frame. Leave a little spare at each end of every board, and when the side is covered run a tenon-saw across both ends of all the boards close to the frame, and finish up with the plane. This is quicker and makes a neater job than cutting each board to size separately.
The Back (Fig. 20).—When laying out the frame for this, remember that there is a bevel to be allowed for along the top, and that the height of the frame at the front must be that of the back of a side frame. (See Fig. 21.) The boards should be cut off to the same slope.
Twenty-four boards should exactly cover the back. Cut the tongue neatly off that last fixed, and glue it into the groove of the first board.
The Front.—The frame requires careful making. For details of corner joints see Fig. 16. The 3-inch faces of the top and bottom bars are vertical. The upper side of the top bar is planed off to the angle of the slope. (Fig. 23.)
The Doors (Fig. 22).—These are the most difficult parts to construct, as the braces which prevent the front edges dropping must be carefully fitted in order to do their work properly.
The eleven outside boards of each door are held together by two 4-inch ledges 6 inches away from the ends, and one 5-inch central ledge. Allow a little "spare" on the boards for truing up. Boards and ledges having been nailed together, lay a piece of 4 by 1-1/2 inch batten across the ledges on the line which the braces will take, and mark the ledges accordingly. Next mark on the batten the ends of the braces. These project half an inch into the ledges, and terminate on the thrust side in a nose an inch long, square to the edge of the brace. The obtuse angle is flush with the edge of the ledge. Cut out the braces, lay them in position on the ledges, and scratch round the ends. Chisel out the notches very carefully, working just inside the lines to ensure the brace making a tight fit. If there is any slackness at either end, the brace obviously cannot carry the weight of the door until the door has settled slightly, which is just what should be prevented. Therefore it is worth while taking extra trouble over this part of the work.
Cautions.—Don't get the nose of the brace too near the end of the ledge. Nail the boards on specially securely to the ledges near the ends of the braces.
Fitting the Doors.—The doors should now be laid on the top of the frame and secured to it by the four hinges. The long ends of these are held by screws driven through the boards into the bearers; the cross pieces are screwed to the uprights of the door frame. The doors when closed should make a good but not tight fit with one another.
PUTTING THE PARTS TOGETHER.
The two sides, front, and back are now assembled, on a level surface, for drilling the holes for the bolts which hold them together. The positions of the bolts will be gathered from the drawings. Get the parts quite square before drilling, and run the holes through as parallel to the sides as possible. If the bolts are a bit too long, pack washers between nut and wood until the nut exerts proper pressure.
Caution.—The hole must not be large enough to allow the square part just under the head to revolve, for in such a case it would be impossible to screw up the nut. Its size ought to be such as to require the head to be driven up against the wood.
The Roof.—The boards of this are attached to a frame which fits closely inside the tops of the sides, back, and front. To get the fit of the frame correct, it must be made a bit too wide in the first instance, and then be bevelled off at the front, as shown in Fig. 23, and the reverse way at the back. The ends are notched for the stays AA, and the frame then tacked firmly, by driving nails into the sides, etc., below it, in the position which it will occupy when the roof is on, except that it projects upwards a little. Cut off twenty-five boards 3 feet 7 inches long. Omitting the end ones for the present, lay the remainder up to one another in order, their ends an equal distance from the frame, and nail to the frame. Lift off the roof, insert and secure AAAA, and nail on the end boards. Then rule parallel straight lines 3 feet 6 inches apart across all the boards from end to end of the roof, and cut along these lines. The roof is replaced after notches have been cut in the tops of the sides to take AAAA, and secured to the vertical parts by six bolts, the positions of which are shown in Fig. 24.
The Floor (Fig. 25).—The making of this is so simple a matter that one need only point out the need for notching the end boards to allow the floor to touch the sides and back, and the doors when closed. It should be screwed to the frames, on which it rests, in a few places.
Preserving the Wood.—All outside wood is dressed with stoprot or creosote, rubbed well into the joints of the boarding.
Felting the Roof.—The felt is cut into 4-foot lengths, and each length has its ends turned over and nailed to the underside of the roof. The strips must overlap an inch or two. When the felt is on, dress it with boiled tar, and sprinkle sand over it while the tar is still liquid.
Fitting.—The two bolts to hold one door top and bottom and the lock are now fitted, and a couple of hooks screwed into the door frame clear of the door, to sling a machine from while it is being cleaned or adjusted.
Mounting the Shed.—The shed must be raised a few inches above the ground, on bricks or other suitable supports. Don't stand it close to a wall. Air should be able to circulate freely under and all round it.
CUTTING DOWN EXPENSE.
If the cost appears prohibitive, it may be reduced somewhat (1) by using thinner boards; (2) by reducing the height of the shed by 1 foot. A very cheap shed, but of course not comparable in quality with the one described, can be made by using odd rough boards for the outside, and covering them with roofing felt well tarred.
VIII. A TARGET APPARATUS FOR RIFLE SHOOTING.
The base is a 1-inch board, 18 inches long and 7 inches wide.
The target-holder is a piece of wood 1-1/2 inches square, and a couple of inches longer than the side of the largest target to be used. To one face nail a piece of strip lead as weight; and to the parallel face attach, by means of brads driven in near one edge, a piece of thin wood of the same size as the face. The free long edge of this should be chamfered off slightly on the inside to enable the target to be slipped easily between it and the roller.
The roller is pivoted on two short spindles—which can be made out of stout wire nails—driven into the ends near the face farthest from the weight. (See Fig. 26.)
For standards use a couple of the small angle irons used for supporting shelves, and sold at about a penny each. These are screwed on to the board 2 inches from what may be considered to be the rear edge, and are so spaced as to leave room for a washer on each spindle between the roller and the standards, to diminish friction.
Remove one standard, and drive into the roller a piece of stout wire with its end bent to form an eye. The inclination of the arm to the roller is shown in Fig. 26.
To the front of the board now nail a rectangle of stout sheet iron, long and deep enough to just protect the standards and roller. Place the roller in position, insert a target, and revolve the roller to bring the target vertical. A small wire stop should now be fixed into the baseboard to prevent the arm coming farther forward, and a hole for the operating string be drilled in the protection plate at the elevation of the eye on the arm. The edges of this hole need careful smoothing off to prevent fraying of the string. A small eyelet or brass ring soldered into or round the hole will ensure immunity from chafing.
Drive a couple of long wire nails into the front edge of the board outside the iron screen to wind the string on when the target is put away.
It may prove a convenience if plain marks are made on the string at the distances from which shooting will be done.
The above description covers apparatus for working two or more targets simultaneously on a long roller, or separately on separate rollers mounted on a common baseboard.
If it is desired to combine with the apparatus a "stop" for the bullets, the latter (a sheet of stout iron of the requisite strength) may be affixed to the rear of the baseboard, and furnished with a handle at the top to facilitate transport.
IX. CABINET-MAKING.
A Match-box Cabinet.
This is useful for the storage of small articles, such as stamps, pens, seeds, needles, and a number of other minor things which easily go astray if put in a drawer with larger objects.
The best boxes for the purpose are those used for the larger Bryant and May matches. Select only those boxes of which the tray moves easily in the case.
The cases should be stood on end on some flat surface while being glued together. A box or drawer with truly square corners is useful for assembling them in; if they are packed into one corner they cannot slew about. Press the boxes together while the glue is setting.
Now glue the back ends of the cases (from which the trays should have been removed), and press them against a piece of thin card. When the glue is dry, apply some more with a small brush to the back angles inside the covers, to ensure a good hold on the backing. Trim off the card to the outline of the pile.
Select for the front end of the drawer that for which the wood is doubled over. Paste outside the end a piece of white paper, whereon words and numbers will be more plainly visible. The life of the trays will be increased if the insides are neatly lined with thin paper.
For "handles" use boot buttons, or loops of thin brass wire, or brass paper clips. To give the cabinet a neat appearance you should cover it outside with paper of some neutral tint; and if you wish it to be stable and not upset when a rather sticky drawer is pulled out, glue it down to a solid wooden base of the proper size.
A Cardboard Cabinet.
We now proceed to a more ambitious undertaking—the manufacture of a cabinet for the storage of note-paper, envelopes, labels, etc. The only materials needed are some cardboard and glue; the tools, a ruler and a very sharp knife. For the marking out a drawing board and T-square are invaluable. The cardboard should be fairly stout, not less than 1/16 inch thick.
Begin with the drawers; it is easier to make the case fit the drawers than vice versa.
Mark out the drawers as shown in Fig. 28. The areas AA are the front and back; BB the sides. The dotted lines indicate the lines along which the cardboard is bent up. The sides are of exactly the same length as the bottom, but the front and back are longer than the bottom by twice the thickness of the cardboard, so as to overlap the sides. (The extra length is indicated by the heavy black lines.)
Measure and cut out very carefully to ensure all the drawers being of the same size. Lay a piece of card under the thing cut to avoid blunting the knife or damaging the table. When the blanks are ready, cut them almost through along the dotted lines. Use several strokes, and after each stroke test the stubbornness of the bend. When the card is almost severed it will bend up quite easily. Note.—Bend as shown in the inset C; not the other way, or you will snap the card. If you should be so unlucky as to cut the card through in places, paste a strip of thin paper along the line before turning up.
The four flaps are now bent up, glued together, and covered outside with paper. This part of the business is easy enough if a small square-cornered wooden box be used as a support inside at each angle in turn. It is advisable to glue strips along all the bends both inside and outside. The external strips should be flattened down well, so as to offer no loose edges.
Compare the drawers, and if one is slightly wider than the rest, use it to guide you in making the measurements for the case.
The sides and back of the case are cut out of a single piece. The sides should be a quarter of an inch deeper than the drawers to allow some overlap; the back slightly wider than the drawer.
As each drawer will be separated from that above it by a shelf, allowance must be made for the shelves, and also for a twentieth of an inch or so of "play" to each drawer. To keep on the safe side leave a little extra stuff to be removed later on.
Cut out the bottom to fit inside the back and sides exactly, and a sufficient number of shelves of precisely the same size as the bottom. Attach the bottom to the sides and back with internal and external strips. When the glue has set, place the guide drawer in position, and lay on it a piece of thin card to cover it over. This card is merely a removable "spacer." Along the side and back edges of the shelf stick projecting strips of stout paper. When the adhesive is dry, turn the strips round the end at right angles to the division, glue them outside, and lay the division in position on top of the "spacer."
Place the second drawer and shelf in like manner, and continue till the top of the cabinet is reached. Then mark off and cut away any superfluous card. Glue the top edges, and stand the cabinet head downwards on a piece of cardboard. Trim off the edges of this, and the top is completed, except for binding the corners.
Then attend to the outside back corners of the case, and paste strips in the angles under the shelves. The strips should be forced well into the angles.
For handles use brass rings let sufficiently far through the fronts of the drawers for a wedge of card to be slipped through them and stuck in position. The appearance of the cabinet will be enhanced by a neatly applied covering of paper.
A Cigar-box Cabinet.
At the rate of a halfpenny or less apiece one may buy the cigar boxes made to hold twenty-five cigars. These boxes, being fashioned by machinery, are all—at any rate all those devoted to a particular "brand"—of the same dimensions; they are neatly constructed, and their wood is well seasoned. Anyone who wishes to make a useful little cabinet may well employ the boxes as drawers in the said cabinet (Fig. 29).
Each box should be prepared as follows:-Remove the lid and paper lining, and rub all the paper binding off the outside angles with a piece of coarse glass paper. This is a safer method than soaking-off, which may cause warping and swelling of the wood. Then plane down the tops of the two sides till they are flush with the back and front, and glue into the corners small pieces of wood of right-angled-triangle section to hold the sides together and the bottom to the sides. To secure the parts further cut a number of large pins down to 3/4 inch, and drive these into the sides through holes carefully drilled in the bottom. Finally, rub the outside of the drawer well with fine glass paper or emery cloth till the surface is smooth all over.
The Case.—If mahogany can be obtained for this, so much the better, as the wood will match the boxes. In default of it, a white wood, stained, will have to serve.
The two sides of the case should be prepared first Wood 3/8 inch thick is advised. Each side is 1 inch wider than the depth (outside) of a drawer from front to back. (Whether the drawers shall slide in lengthways or flatways is for the maker to decide.) The length of a side is calculated on the basis that the drawers will be separated from one another by runners 1/4 to 5/16 inch deep, and that a slight clearance must be allowed for the drawers to slide in and out freely. In the first instance cut the sides a bit too long. If it be preferred to insert the bottom between the sides, the length must be increased accordingly.
The runners are cut out of the box lids, and planed till their top and bottom edges are parallel. Their length is 1/4 inch less than the depth of a drawer. To fill up the spaces between the drawers in front you will need some slips of the same depth as the runners, and 3/8 inch longer than the drawer, so that they may be let 3/16 inch into the sides of the case at each end.
Affixing the Runners.—This is a very easy matter if a wooden spacer, slightly wider than the depth of the drawer, is prepared. Having decided which is to be the inside face and the forward edge of a side, lay the side flat, and apply the spacer with one edge flush with the bottom of the side, or as far away from it as the thickness of the bottom, as the case may be, and fix it lightly in position with a couple of tacks. The first runner is laid touching the spacer and a little back from the edge to give room for the cross-bar, and fastened by means of short tacks, for which holes had better be drilled in the runner to prevent splitting. The spacer is now transferred to the other side of the runner, and the second runner is fastened on above it; and so on till all the runners are in position. The square should be used occasionally to make sure that the tops of the runners are parallel to one another. The other side having been treated in like manner, any spare wood at the top is sawn off.
The notches for the front cross-bars between drawers are cut out with a very sharp narrow chisel.
The Top and Bottom.—Make the top of the same thickness as the sides; the bottom of somewhat stouter wood. If the bottom is cut a bit longer than the width of the case, and neatly bevelled off, it will help to smarten the appearance of the cabinet.
When fixing the sides to the bottom and top get the distance correct by placing the top and bottom drawers in position, and insert a piece of thin card between one end of the drawer and the side. This will ensure the necessary clearance being allowed for.
The Back.—Cut this out of thin wood. The top of a sweetstuff box-costing about a halfpenny—will do well enough. It should be quite rectangular and make a close fit, as it plays the important part of keeping the case square laterally. Bevel its back edges off a bit. Push it in against the back ends of the runners, and fix it by picture brads driven in behind.
The front bars should now be cut to a good fit and glued in the notches. This completes the construction.
Drop handles for the drawers may be made out of semicircles of brass wire with the ends turned up. The handles are held up to the drawer by loops of finer wire passed through the front and clinched inside.
The finishing of the outside must be left to the maker's taste. Varnishing, or polishing with warmed beeswax, will add to the general appearance, and keep out damp.
The total cost of a ten-drawer cabinet ought not to exceed eighteen pence.
A Tool Cabinet.
The wooden cabinet shown in Fig. 30 is constructed, as regards its case, in the same way as that just described, but the drawers are built up of several pieces. The over-all dimensions of the cabinet represented are as follows: Height, including plinth, 25 inches; width, 17-3/8 inches; depth, 10-1/2 inches. The drawers are 16 inches wide (outside), by 10-1/8 inches from back to front, and, reckoning from the bottom upwards, are 3-1/4, 3, 2-1/2, 2, 2, 2, 2, and 1-3/4 inches deep.
The construction of the drawers is indicated by the diagrams, Fig. 30, b, c, d. The fronts are of 5/8-inch, the sides and backs of 3/8-inch, and the bottoms of (barely) 1/4-inch wood. The grooves should not come nearer than 1/8-inch to the bottom edge, or be more than 5/16 inch wide and deep. The possessor of a suitable "plough" plane will have no difficulty in cutting them out; in the absence or such a tool the cutting gauge and chisel must be used.
The back piece of a drawer has 1/4-inch less height than the front, to allow the bottom to be introduced. The ends or the bottom are bevelled off towards the top edge to fit the grooves, so that no part may be above the grooves.
Glue should be used to attach the sides of a drawer to the back and front in the first place, and nails be added when the glue has set. As an aid to obtaining perfect squareness, without which the drawers will fit badly, it is advisable to mark out on a board a rectangle having the exact inside dimensions of a drawer, and to nail strips of wood up to the lines on the inside. If the parts are put together round this template they will necessarily fit squarely.
Divisions.—If the drawers are to be subdivided in one direction only, the partitions should run preferably from back to front, as this enables the contents of a compartment to be more easily seen. Where two-direction division is needed the partitions are cut as shown in Fig. 31. All partitions should touch the bottom, and be made immovable by gluing or nailing. It is a mistake to have so many divisions in a drawer that the fingers cannot get into them easily.
Wooden knobs for the drawers can be bought very cheaply of any turner, or suitable brass knobs at any ironmonger's. Take care that the knobs are in line with one another; otherwise the general appearance of the cabinet will suffer.
Lock and Key.—If a cabinet is intended for storage of articles of any value it should be provided with lock and key. One lock will secure all the drawers if attached to a flap hinged on one side to the cabinet, as shown in Fig. 30 a, to engage a catch projecting from one of the drawers. A special form of lock is sold for the purpose. If the single flap seems to give a lop-sided effect, place a fellow on the other side, and fit it with sunk bolts to shoot into the overhanging top and plinth. If you wish to avoid the expense and trouble of fitting a lock, substitute a padlock and a staple clinched through the front of a drawer and passing through a slot in the flap (Fig. 30, e).
Alternative Method.—The fixing of the front bars can be avoided if the front of each drawer (except the lowest) be made to overhang the bottom by the depth of the runner. This method, of course, makes it impossible to stand a drawer level on a level surface.
X. TELEGRAPHIC APPARATUS.
The easily made but practical apparatus described in this chapter supplies an incentive for learning the Morse telegraphic code, which is used for sending sound signals, and for visible signals transmitted by means of flags, lamps, and heliograph mirrors. Signalling is so interesting, and on occasion can be so useful, that no apology is needed for introducing signalling apparatus into this book.
The apparatus in question is a double-instrument outfit, which enables an operator at either end of the line to cause a "buzzer" or "tapper" to work at the other end when he depresses a key and closes an electric circuit. Each unit consists of three main parts—(1) the transmitting key; (2) the receiving buzzer or tapper; (3) the electric battery.
The principles of an installation are shown in Fig. 33. One unit only is illustrated, but, as the other is an exact duplicate, the working of the system will be followed easily.
A wooden lever, L, is pivoted on a support, A. Passing through it at the forward end is a metal bar having at the top a knob, K, which can be grasped conveniently in the fingers; at the other a brass screw, O, which is normally pulled down against the contact, N, by the spiral spring, S. The contact M under K is in connection with the binding post T1 and N with binding post T3; K is joined up to T2, and O to T4.
T3 and T4 are connected with one of the line wires; T1 with the other wire through a battery, B; T3 with the other wire through the buzzer, R. [1]
[Footnote 1: For the buzzer may be substituted the tapper, described on a later page.]
Assuming both keys to be at rest, as in Fig. 33, the two buzzers are evidently in circuit with the line wires, though no current is passing. If the stem of K is depressed to make contact with M, the electric circuit of which the battery, B, forms part is completed, and the buzzer at the other end of the lines comes into action. Since the depression of K raises O off N, the "home" buzzer's connection with the line wires is broken, to prevent the current being short-circuited. The fact that this buzzer is periodically in circuit, even when the key is being worked, makes it possible for the operator at the other end to attract attention by depressing his key, if he cannot read the signals sent.
Making the Keys.
Transmitting keys can be bought cheaply, but not so cheaply as they can be made. The only expense entailed in home manufacture is that of the screw terminals for connecting the keys with the lines and buzzers. These cost only a penny each, and, if strict economy is the order of the day, can be dispensed with should the apparatus not have to be disconnected frequently.
The size of the key is immaterial. The keys made by me have levers 1 inch wide and 5-1/2 inches long, oak being chosen as material, on account of its toughness. K is in each case a small wooden knob on a piece of 3/16-inch brass rod; O a 1-1/2-inch brass screw; A a piece of sheet brass 3-1/2 inches long, marked off carefully, drilled 1/8 inch from the centre of each end for the pivot screws, and in four places for the holding-down screws, and bent up at the ends to form two standards. If you do not possess any brass strip, the lever may be supported on wooden uprights glued and screwed to the base.
Contact M is a small piece of brass attached to the base by a screw at one end and by T1 at the other. K was drilled near the end to take the short coil of insulated wire joining it to T2, and O was similarly connected with T4.
The spring, S, should be fairly strong. A steel spiral with a loop at each end is most easily fitted. Drill holes in the lever and base large enough for the spring to pass through freely, make a small cross hole through the lever hole for a pin, and cut a slot across the base hole for a pin to hold the bottom of the spring. Adjust the lever by means of screw O so that there is a space of about 1/4-inch between K and M when O and N are in contact, and after the spring has been put in position give the screw a turn or two to bring K down to within 1/16 inch of M. This will put the required tension on the spring.
The Buzzers.—For these I selected a couple of small electric bells, costing 2s. 6d. each. Their normal rate of vibration being much too slow for telegraphic purposes, I cut off the hammers to reduce the inertia, and so adjusted the contact screw that the armature had to move less than one hundredth of an inch to break the circuit. This gave so high a rate of vibration that the key could not make and break the circuit quickly enough to prevent the buzzer sounding.
A Morse Tapper or Sounder.
In postal telegraph offices a "sounder," and not a "buzzer," is generally used to communicate the signals. Instead of a continuous noise, lasting as long as the key at the transmitting station is held down, the operator at the receiving station hears only a series of taps made by an instrument called a "sounder." The principle of this simple device is illustrated by the working diagrams in Fig. 35. M is a horseshoe magnet fixed to a base, A. Close to it is an armature, AR, of soft iron, attached to a lever, L, which works on a pivot and is held up against a regulating screw, P1, by the pull of the spring SP. When current passes through the magnet the armature is attracted, and the point of the screw S2 strikes against P2; while the breaking of the circuit causes L to fly back against S1. The time intervening between the "down" and "up" clicks tells the operator whether a long or a short—dash or a dot—is being signalled.
Materials.—A horseshoe magnet and armature taken from an electric bell provide the most essential parts of our home-made instrument in a cheap form. If these are available, expense will be limited to a few pence. Oak or walnut are the best woods to use for the lever, being more resonant than the softer woods, and for the standard B and stop V. Any common wood is good enough for the base A.
The lever L is 6 inches long, 1/2 inch deep, and 3/8-inch wide, and is pivoted at a point 4-1/4 inches from the stop end. The hole should be bored through it as squarely as possible, so that it may lie centrally without B being out of the square. A piece of metal is screwed to its top face under the adjusting screw S1.
The spring is attached to L and A in the manner already described on p. 89 in connection with the "buzzer."
The plate P2 should be stout enough not to spring under the impact of the lever. Fig. 36 is an end view of the standard B. The drilling of the pivot hole through this requires care. The screw S2 should be so adjusted as to prevent the armature actually touching the cores of the magnets when attracted. The ends of the magnet winding wire, after being scraped, are clipped tightly against the base by the binding posts T1 T2.
If sounders are used in place of buzzers they are connected up with the keys, batteries, and line wires in the manner shown in Fig. 33.
Batteries.
The dry cells used for electric bells are the most convenient batteries to use. They can now be purchased at all prices from a shilling upwards, and give about 1-1/2 volts when in good condition. One cell at each end will suffice for short distances, or for considerable distances if large conductors are used. If a single cell fails to work the buzzer strongly through the circuit, another cell must be added.
For ease in transport it will be found advisable to mount key, buzzer, and battery on a common baseboard, which should be provided with a cover and handle. The three parts are interconnected with one another, and the line wire terminals as sketched in Fig. 34. This arrangement makes the apparatus very compact and self-contained. As a finishing touch fit the lid inside with clips for holding a stiff-backed writing pad and pencil for the recording of messages.
Lines.—Fencing made of stout galvanized iron wires strung on wooden posts supplies excellent conductors for practice purposes, provided the posts be quite dry. In wet weather there will be leakage. (Fencing with metal posts is, of course, unsuitable, as every post short-circuits the current.) The two wires selected for land lines must be scraped quite bright at the points where the connections are to be made.
It is an easy matter to rig up a telegraph line of galvanized wire 1/12 to 1/8 inch in diameter, strung along insulators (the necks of bottles serve the purpose excellently) supported on trees, posts, or rough poles. The length of the line will be limited by the battery power available, but a 6-volt battery at each end will probably suffice for all experimental purposes. A second wire is not needed if one terminal at each end is connected with a copper plate sunk in the ground, or with a metal fence, drain-pipe, etc.
XI. A RECIPROCATING ELECTRIC MOTOR.
The electric motor to be treated in this chapter illustrates very prettily the attractive force of a hollow, wire-wound bobbin on a movable core, when the electric current is passed through the wire. If one inserts the end of an iron rod into the coil, the coil exerts a pull upon it, and this pull will cease only when the centre of the rod is opposite the centre of the coil. This principle is used in the "electric gun," which in its simplest form is merely a series of powerful coils arranged one behind another on a tube through which an iron or steel projectile can pass. The projectile closes automatically the circuit of each coil in turn just before reaching it, and breaks it before its centre is halfway through the coil, being thus passed along from one coil to the other with increasing velocity.
Our motor is essentially a very inefficient one, its energy being small for the current used, as compared with a revolving motor of the usual kind. But it has the advantage of being very easy to make.
How it works.—The experimental engine, constructed in less than a couple of hours, which appears in Fig. 38, consists of a coil, C, strapped down by a piece of tin to a wooden bedplate; a moving plunger, P, mounted on a knitting-needle slide rod, SR; a wire connecting rod, SR; a wooden crank, K; and a piece of knitting-needle for crank shaft, on which are mounted a small eccentric brass wipe, W, and a copper collar, D. Against D presses a brass brush, B1 connected with the binding post, T1; while under W is a long strip of springy brass against which W presses during part of every revolution. T2 is connected to one end of the coil winding, and T1 through a 4-volt accumulator or three dry cells, with the other end of the coil. When W touches B2 the circuit is completed, and the coil draws in the plunger, the contact being broken before the plunger gets home. The crank rotates at a very high speed if there is plenty of battery power, all the moving parts appearing mere blurs.
CONSTRUCTION.
The coil is made by winding 4 oz. of No. 32 cotton-covered wire (price 6d. to 8d.) on a boxwood reel 2 inches long and 1-1/2 inches in diameter, with a 9/16-inch central hole. Before winding, bore a hole for the wire through one end of the reel, near the central part, and mount the reel on a lathe or an improvised spindle provided with a handle of some kind. The wire should be uncoiled and wound on some circular object, to ensure its paying out regularly without kinking; which makes neat winding almost impossible.
Draw a foot of the wire through the hole in the reel, and drive in a tiny peg—which must not protrude inwards—to prevent it slipping. Lay the turns on carefully, forcing them into close contact, so that the next layer may have a level bed. On reaching the end of the layer, be equally careful to finish it neatly before starting back again. When the wire is all on, bore a hole as near the edge of the finishing edge as possible, and draw the spare wire through. Then cut a strip of tough paper of the width of the coils, coat one side with paste, and wrap it tightly round the outside to keep the wire in place.
Note.—Insulation will be improved if every layer of wire is painted over with shellac dissolved in alcohol before the next layer is applied.
Flatten the reel slightly with a file at the points of contact with the baseboard, to prevent rolling.
The plunger is a tube of thin iron, 1/16 inch less in diameter than the hole in the reel, and 1/4 inch longer than the reel. If a ready-made tube is not available, construct one by twisting a piece of tin round a metal rod, and soldering the joint. As it is difficult to make a jointed tube cylindrical, and a close fit is needed to give good results, it is worth going to a little trouble to get a plunger of the right kind.
The ends of the plunger are plugged with wood and bored centrally for the slide rod, which should not be cut to its final length until the parts are assembled.
The crank shaft is 2-3/4 inches of a stout knitting needle mounted in a sheet brass bearing. The crank, a fragment of oak or other tough wood, is balanced, and has a throw of 5/8 inch. The crank-shaft hole should be a trifle small, so that the crank shall get a tight hold of the shaft without pinning. The collar, D, and wipe, W, are soldered to the shaft after this has been passed through its bearings. The brush B1 should press firmly, but not unnecessarily so, against the collar. For B2 one must use very springy brass strip, a piece about 3 inches long and 1/4 inch wide being needed. Bend it to the arc of a large circle, and screw one end down to the base by the binding screw T2. The other end, which should not touch the base, is confined by the heads of a couple of small screws, by means of which the strip is adjusted relatively to the wipe.
Fixing the Coil.—Cut a strip of tin 1-3/4 inches wide and 4 inches long. Punch a couple of holes near one end, and nail this to the side of the base, with its forward end 4-1/4 inches from the crank shaft. Pass the strip over the coil, and bend it down towards the base. Drill a couple of screw holes, and screw the other end down so that the coil is gripped fairly tight.
Fixing the Plunger. Two small guides, G1 G2, are made for the plunger. The holes through which the slide rod moves should be a good fit, and their centres at the level of the centre of the coil. Screw holes are bored in the feet.
Pass the plunger through the coil, and place the guides on the rod. Then draw the plunger forward till 1/2 inch projects. Bring G1 close up to it, mark its position, and screw it to the base. The other guide, G2, should be 1-1/2 inches away from the rear of the coil.
The coil and guides must be adjusted so that the plunger does not touch the coil anywhere during a stroke, packings being placed, if necessary, under coil or guides. When the adjustment is satisfactory, screw the coil down tightly, and cut off any superfluous parts of the rod.
The Connecting Rod.—Bore a hole near the end of the plunger for a screw to hold the rear end of the connecting rod. Pull the plunger out till 1-3/4 inches project, turn the crank full forward, and measure off the distance between the centres of the plunger hole and the crank pin. Drive a couple of wire nails into a board, and twist the ends of a piece of 1/20-inch wire round them twice. This wire constitutes a connecting rod amply strong enough to stand the pulls to which it will be subjected. Fix the rod in position.
Adjusting the Wipe.—Turn the wipe, W, round until it makes contact with B2, and, holding the crank shaft with a pair of pliers, twist the crank on it till it just begins the return stroke. Then turn the crank to find out how long the wipe remains in contact, and adjust the crank relatively to the wipe so that the crank is vertical when the period of contact is half finished. The length of this period is controlled by the set screws at the free end of B2.
OTHER DETAILS.
The fly wheel may be a disc of wood.
Oil all the rubbing parts slightly. Connect T1 to one terminal of the battery, T2 to the coil, and the other terminal of the battery to the coil. Set the engine going. If it refuses to run, make sure that B1 is pressing against D. The speed of the engine may possibly be improved by careful adjustment of B2 and an alteration in the setting of the crank, and will certainly be accelerated by increasing the number of battery cells.
The cost of the engine described was about 1s, 3d., exclusive of the battery.
XII. AN ELECTRIC ALARM CLOCK.
Anybody who possesses an alarm clock with an external gong, an electric bell, and a battery, may easily make them combine to get the drowsiest of mortals out of bed on the chilliest of winter mornings. The arrangement has as its secondary advantages and capabilities—
(l) That the clock can be placed where its ticking will not disturb the person whom it has to arouse in due course (some of the cheaper clocks are very self-advertising);
(2) That one clock can be made to operate any number of bells in different parts of the house.
The main problem to be solved is, how to make the alarm mechanism of the clock complete an electric circuit when the alarm "goes off."
If you examine an alarm clock of the type described, you will find that the gong hammer lies against the gong when at rest, and that its shaft when in motion vibrates to and fro about a quarter of an inch.
Fig. 39 shows a. method of utilizing the movement of the hammer. A piece of wood, 2 inches long, wide enough to fill the space between the rear edge of the clock and the hammer slot, and 1/2 inch thick, has its under side hollowed out to the curvature of the clock barrel. This block serves as a base for two binding posts or terminals, T1 T2. A vertical slit is made in T1 and in this is soldered [to] one end of a little piece of spring brass strip, 1 inch long and 1/4 inch wide. To the back of the other end of the strip solder a piece of 1/20 inch wire, projecting l inch below the strip. The strip must be bent so that it presses naturally against T2. A little trigger, B, which you can cut out of sheet brass, is pivoted at a, where it must be raised off the base by a small washer. It projects 1/4 inch beyond the base on the gong support side. A square nick is cut in it at such a distance from a that, when the wire spike on C is in the nick, the strip is held clear of T2. The other end of the trigger, when the trigger is set, must be 1/8 inch from the shank of the alarm hammer—at any rate not so far away that the hammer, when it vibrates, cannot release C from the nick.
To fix the base on to the top of the clock, the works must be removed (quite an easy matter to accomplish) and holes bored for a couple of screws put through from the inside. If the underside of the base is not quite correctly curved, take care not to force in the screws far enough to distort the barrel. It is advisable to do the fitting of the parts of the release after the base has been fixed, and before the works are replaced. The position of the hammer shaft can be gauged accurately enough from the slot in the case.
The tails of the terminals T1 T2 must be truncated sufficiently not to penetrate the base and make contact with the barrel, or a "short circuit" will be evident as soon as the battery is connected up.
If the bell, battery, and clock are in the same room, a single dry cell will give sufficient current; but if the circuit is a long one, or several bells have to be operated, two or more cells will be required.
An Alternative Arrangement.—Should the reader prefer to have the clock quite free from the release—and this is certainly convenient for winding and setting the alarm—he should make a little wooden case for the clock to stand in, just wide enough to take the clock, and the back just as high as the top of the barrel. The release is then attached to a little platform projecting from the back, care being taken that the lever is arranged in the correct position relatively to the hammer when the clock is pushed back as far as it will go (Fig. 40).
If a self-contained outfit is desired, make the case two-storied: the upper division for the clock, the lower for the cell or cells. The bell may be attached to the front. A hinged fretwork front to the clock chamber, with an opening the size of the face; a door at the back of the cell chamber; and a general neat finish, staining and polishing, are refinements that some readers may like to undertake.
Setting the Alarm.—A good many alarm clocks are not to be relied upon to act within a quarter of an hour or so of the time to which they are set. But absolute accuracy of working may be obtained if the clock hands are first set to the desired hour, and the alarm dial hand revolved slowly till the alarm is released. The hands are then set at the correct time, and the alarm fully wound.
XIII. A MODEL ELECTRIC RAILWAY.
The rapid increase in the number of electrically worked railways, and the substitution of the electric for the steam locomotive on many lines, give legitimate cause for wondering whether, twenty or so years hence, the descendants of the "Rocket" will not have disappeared from all the railways of the world, excepting perhaps those of transcontinental character.
The change is already spreading to model plant, and not without good reason, as the miniature electric railway possesses decided advantages of its own. Instead of having to chase the locomotive to stop or reverse it, one merely has to press a button or move a switch. The fascinations of a model steam locomotive, with its furnace, hissing of steam, business-like puffings, and a visible working of piston and connecting rods, are not to be denied, any more than that a full-sized steam locomotive is a more imposing object at rest or in motion than its electric rival. On the other hand, the ease of control already noticed, and the absence of burning fuel, water leakage, smoke and fumes, are strong points in favour of the electric track, which does no more harm to a carpet than to a front lawn, being essentially clean to handle. Under the head of cost the electric locomotive comes out well, as motors can be purchased cheaply; and connecting them up with driving wheels is a much less troublesome business than the construction of an equally efficient steamer. One may add that the electric motor is ready to start at a moment's notice: there is no delay corresponding to that caused by the raising of steam.
The Track
We will consider this first, as its design must govern, within certain limits, the design of the locomotive. There are three systems of electrical transmission available. |
|
