Red tape should for once be disregarded, and a competent commission forthwith sent to 30 Rue d'Assas, with instructions to report immediately, for every minute saved may avoid suffering for Englishmen fighting abroad for their country. I may, of course, be mistaken, but a commission would decide, and if the apparatus is good the slightest delay in its adoption would be deplorable.—Paris Correspondence London Times.

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HOW TO ESTABLISH A TRUE MERIDIAN.

[Footnote: A paper read before the Engineers' Club of Philadelphia.]

By PROFESSOR L. M. HAUPT.

INTRODUCTORY.

The discovery of the magnetic needle was a boon to mankind, and has been of inestimable service in guiding the mariner through trackless waters, and the explorer over desert wastes. In these, its legitimate uses, the needle has not a rival, but all efforts to apply it to the accurate determination of permanent boundary lines have proven very unsatisfactory, and have given rise to much litigation, acerbity, and even death.

For these and other cogent reasons, strenuous efforts are being made to dispense, so far as practicable, with the use of the magnetic needle in surveying, and to substitute therefor the more accurate method of traversing from a true meridian. This method, however, involves a greater degree of preparation and higher qualifications than are generally possessed, and unless the matter can be so simplified as to be readily understood, it is unreasonable to expect its general application in practice.

Much has been written upon the various methods of determining, the true meridian, but it is so intimately related to the determination of latitude and time, and these latter in turn upon the fixing of a true meridian, that the novice can find neither beginning nor end. When to these difficulties are added the corrections for parallax, refraction, instrumental errors, personal equation, and the determination of the probable error, he is hopelessly confused, and when he learns that time may be sidereal, mean solar, local, Greenwich, or Washington, and he is referred to an ephemeris and table of logarithms for data, he becomes lost in "confusion worse confounded," and gives up in despair, settling down to the conviction that the simple method of compass surveying is the best after all, even if not the most accurate.

Having received numerous requests for information upon the subject, I have thought it expedient to endeavor to prepare a description of the method of determining the true meridian which should be sufficiently clear and practical to be generally understood by those desiring to make use of such information.

This will involve an elementary treatment of the subject, beginning with the

DEFINITIONS.

The celestial sphere is that imaginary surface upon which all celestial objects are projected. Its radius is infinite.

The earth's axis is the imaginary line about which it revolves.

The poles are the points in which the axis pierces the surface of the earth, or of the celestial sphere.

A meridian is a great circle of the earth cut out by a plane passing through the axis. All meridians are therefore north and south lines passing through the poles.

From these definitions it follows that if there were a star exactly at the pole it would only be necessary to set up an instrument and take a bearing to it for the meridian. Such not being the case, however, we are obliged to take some one of the near circumpolar stars as our object, and correct the observation according to its angular distance from the meridian at the time of observation.

For convenience, the bright star known as Ursae Minoris or Polaris, is generally selected. This star apparently revolves about the north pole, in an orbit whose mean radius is 1 deg. 19' 13",[1] making the revolution in 23 hours 56 minutes.

[Footnote 1: This is the codeclination as given in the Nautical Almanac. The mean value decreases by about 20 seconds each year.]

During this time it must therefore cross the meridian twice, once above the pole and once below; the former is called the upper, and the latter the lower meridian transit or culmination. It must also pass through the points farthest east and west from the meridian. The former is called the eastern elongation, the latter the western.

An observation may he made upon Polaris at any of these four points, or at any other point of its orbit, but this latter case becomes too complicated for ordinary practice, and is therefore not considered.

If the observation were made upon the star at the time of its upper or lower culmination, it would give the true meridian at once, but this involves a knowledge of the true local time of transit, or the longitude of the place of observation, which is generally an unknown quantity; and moreover, as the star is then moving east or west, or at right angles to the place of the meridian, at the rate of 15 deg. of arc in about one hour, an error of so slight a quantity as only four seconds of time would introduce an error of one minute of arc. If the observation be made, however, upon either elongation, when the star is moving up or down, that is, in the direction of the vertical wire of the instrument, the error of observation in the angle between it and the pole will be inappreciable. This is, therefore, the best position upon which to make the observation, as the precise time of the elongation need not be given. It can be determined with sufficient accuracy by a glance at the relative positions of the star Alioth, in the handle of the Dipper, and Polaris (see Fig. 1). When the line joining these two stars is horizontal or nearly so, and Alioth is to the west of Polaris, the latter is at its eastern elongation, and vice versa, thus:



But since the star at either elongation is off the meridian, it will be necessary to determine the angle at the place of observation to be turned off on the instrument to bring it into the meridian. This angle, called the azimuth of the pole star, varies with the latitude of the observer, as will appear from Fig 2, and hence its value must be computed for different latitudes, and the surveyor must know his latitude before he can apply it. Let N be the north pole of the celestial sphere; S, the position of Polaris at its eastern elongation; then N S=1 deg. 19' 13", a constant quantity. The azimuth of Polaris at the latitude 40 deg. north is represented by the angle N O S, and that at 60 deg. north, by the angle N O' S, which is greater, being an exterior angle of the triangle, O S O. From this we see that the azimuth varies at the latitude.

We have first, then, to find the latitude of the place of observation.

Of the several methods for doing this, we shall select the simplest, preceding it by a few definitions.

A normal line is the one joining the point directly overhead, called the zenith, with the one under foot called the nadir.

The celestial horizon is the intersection of the celestial sphere by a plane passing through the center of the earth and perpendicular to the normal.

A vertical circle is one whose plane is perpendicular to the horizon, hence all such circles must pass through the normal and have the zenith and nadir points for their poles. The altitude of a celestial object is its distance above the horizon measured on the arc of a vertical circle. As the distance from the horizon to the zenith is 90 deg., the difference, or complement of the altitude, is called the zenith distance, or co-altitude.

The azimuth of an object is the angle between the vertical plane through the object and the plane of the meridian, measured on the horizon, and usually read from the south point, as 0 deg., through west, at 90, north 180 deg., etc., closing on south at 0 deg. or 360 deg..

These two co-ordinates, the altitude and azimuth, will determine the position of any object with reference to the observer's place. The latter's position is usually given by his latitude and longitude referred to the equator and some standard meridian as co-ordinates.

The latitude being the angular distance north or south of the equator, and the longitude east or west of the assumed meridian.

We are now prepared to prove that the altitude of the pole is equal to the latitude of the place of observation.

Let H P Z Q, etc., Fig. 2, represent a meridian section of the sphere, in which P is the north pole and Z the place of observation, then H H will be the horizon, Q Q the equator, H P will be the altitude of P, and Q Z the latitude of Z. These two arcs are equal, for H C Z = P C Q = 90 deg., and if from these equal quadrants the common angle P C Z be subtracted, the remainders H C P and Z C Q, will be equal.

To determine the altitude of the pole, or, in other words, the latitude of the place.

Observe the altitude of the pole star when on the meridian, either above or below the pole, and from this observed altitude corrected for refraction, subtract the distance of the star from the pole, or its polar distance, if it was an upper transit, or add it if a lower. The result will be the required latitude with sufficient accuracy for ordinary purposes.

The time of the star's being on the meridian can be determined with sufficient accuracy by a mere inspection of the heavens. The refraction is always negative, and may be taken from the table appended by looking up the amount set opposite the observed altitude. Thus, if the observer's altitude should be 40 deg. 39' the nearest refraction 01' 07", should be subtracted from 40 deg. 37' 00", leaving 40 deg. 37' 53" for the latitude.

TO FIND THE AZIMUTH OF POLARIS.

As we have shown the azimuth of Polaris to be a function of the latitude, and as the latitude is now known, we may proceed to find the required azimuth. For this purpose we have a right-angled spherical triangle, Z S P, Fig. 4, in which Z is the place of observation, P the north pole, and S is Polaris. In this triangle we have given the polar distance, P S = 10 deg. 19' 13"; the angle at S = 90 deg.; and the distance Z P, being the complement of the latitude as found above, or 90 deg.—L. Substituting these in the formula for the azimuth, we will have sin. Z = sin. P S / sin P Z or sin. of Polar distance / sin. of co-latitude, from which, by assuming different values for the co-latitude, we compute the following table:

AZIMUTH TABLE FOR POINTS BETWEEN 26 deg. and 50 deg. N. LAT.

LATTITUDES Year 26 deg. 28 deg. 30 deg. 32 deg. 34 deg. 36 deg. deg. ' " deg. ' " deg. ' " deg. ' " deg. ' " deg. ' " 1882 1 28 05 1 29 40 1 31 25 1 33 22 1 35 30 1 37 52 1883 1 27 45 1 29 20 1 31 04 1 33 00 1 35 08 1 37 30 1884 1 27 23 1 28 57 1 30 41 1 32 37 1 34 45 1 37 05 1885 1 27 01 1 28 351/2 1 30 19 1 32 14 1 34 22 1 36 41 1886 1 26 39 1 28 13 1 29 56 1 31 51 1 33 57 1 36 17 Year 38 deg. 40 deg. 42 deg. 44 deg. 46 deg. 48 deg. deg. ' " deg. ' " deg. ' " deg. ' " deg. ' " deg. ' " 1882 1 40 29 1 43 21 1 46 33 1 50 05 1 53 59 1 58 20 1883 1 40 07 1 42 58 1 46 08 1 49 39 1 53 34 1 57 53 1884 1 39 40 1 42 31 1 45 41 1 49 11 1 53 05 1 57 23 1885 1 39 16 1 42 07 1 45 16 1 48 45 1 52 37 1 56 54 1886 1 38 51 1 41 41 1 44 49 1 48 17 1 52 09 1 56 24 Year 50 deg. deg. ' " 1882 2 03 11 1883 2 02 42 1884 2 02 11 1885 2 01 42 1886 2 01 11

An analysis of this table shows that the azimuth this year (1882) increases with the latitude from 1 deg. 28' 05" at 26 deg. north, to 2 deg. 3' 11" at 50 deg. north, or 35' 06". It also shows that the azimuth of Polaris at any one point of observation decreases slightly from year to year. This is due to the increase in declination, or decrease in the star's polar distance. At 26 deg. north latitude, this annual decrease in the azimuth is about 22", while at 50 deg. north, it is about 30". As the variation in azimuth for each degree of latitude is small, the table is only computed for the even numbered degrees; the intermediate values being readily obtained by interpolation. We see also that an error of a few minutes of latitude will not affect the result in finding the meridian, e.g., the azimuth at 40 deg. north latitude is 1 deg. 43' 21", that at 41 deg. would be 1 deg. 44' 56", the difference (01' 35") being the correction for one degree of latitude between 40 deg. and 41 deg.. Or, in other words, an error of one degree in finding one's latitude would only introduce an error in the azimuth of one and a half minutes. With ordinary care the probable error of the latitude as determined from the method already described need not exceed a few minutes, making the error in azimuth as laid off on the arc of an ordinary transit graduated to single minutes, practically zero.

REFRACTION TABLE FOR ANY ALTITUDE WITHIN THE LATITUDE OF THE UNITED STATES.

Apparent Refraction Apparent Refraction Altitude. minus. Altitude. minus. 25 deg. 0 deg. 2' 4.2" 38 deg. 0 deg. 1' 14.4" 26 1 58.8 39 1 11.8 27 1 53.8 40 1 9.3 28 1 49.1 41 1 6.9 29 1 44.7 42 1 4.6 30 1 40.5 43 1 2.4 31 1 36.6 44 0 0.3 32 1 33.0 45 0 58.1 33 1 29.5 46 0 56.1 34 1 26.1 47 0 54.2 35 1 23.0 48 0 52.3 36 1 20.0 49 0 50.5 37 1 17.1 50 0 48.8

APPLICATIONS.

In practice to find the true meridian, two observations must be made at intervals of six hours, or they may be made upon different nights. The first is for latitude, the second for azimuth at elongation.

To make either, the surveyor should provide himself with a good transit with vertical arc, a bull's eye, or hand lantern, plumb bobs, stakes, etc.[1] Having "set up" over the point through which it is proposed to establish the meridian, at a time when the line joining Polaris and Alioth is nearly vertical, level the telescope by means of the attached level, which should be in adjustment, set the vernier of the vertical arc at zero, and take the reading. If the pole star is about making its upper transit, it will rise gradually until reaching the meridian as it moves westward, and then as gradually descend. When near the highest part of its orbit point the telescope at the star, having an assistant to hold the "bull's eye" so as to reflect enough light down the tube from the object end to illumine the cross wires but not to obscure the star, or better, use a perforated silvered reflector, clamp the tube in this position, and as the star continues to rise keep the horizontal wire upon it by means of the tangent screw until it "rides" along this wire and finally begins to fall below it. Take the reading of the vertical arc and the result will be the observed altitude.

[Footnote 1: A sextant and artificial horizon may be used to find the altitude of a star. In this case the observed angle must be divided by 2.]

ANOTHER METHOD.

It is a little more accurate to find the altitude by taking the complement of the observed zenith distance, if the vertical arc has sufficient range. This is done by pointing first to Polaris when at its highest (or lowest) point, reading the vertical arc, turning the horizontal limb half way around, and the telescope over to get another reading on the star, when the difference of the two readings will be the double zenith distance, and half of this subtracted from 90 deg. will be the required altitude. The less the time intervening between these two pointings, the more accurate the result will be.

Having now found the altitude, correct it for refraction by subtracting from it the amount opposite the observed altitude, as given in the refraction table, and the result will be the latitude. The observer must now wait about six hours until the star is at its western elongation, or may postpone further operations for some subsequent night. In the meantime he will take from the azimuth table the amount given for his date and latitude, now determined, and if his observation is to be made on the western elongation, he may turn it off on his instrument, so that when moved to zero, after the observation, the telescope will be brought into the meridian or turned to the right, and a stake set by means of a lantern or plummet lamp.



It is, of course, unnecessary to make this correction at the time of observation, for the angle between any terrestrial object and the star may be read and the correction for the azimuth of the star applied at the surveyor's convenience. It is always well to check the accuracy of the work by an observation upon the other elongation before putting in permanent meridian marks, and care should be taken that they are not placed near any local attractions. The meridian having been established, the magnetic variation or declination may readily be found by setting an instrument on the meridian and noting its bearing as given by the needle. If, for example, it should be north 5 deg. east, the variation is west, because the north end of the needle is west of the meridian, and vice versa.

Local time may also be readily found by observing the instant when the sun's center[1] crosses the line, and correcting it for the equation of time as given above—the result is the true or mean solar time. This, compared with the clock, will show the error of the latter, and by taking the difference between the local lime of this and any other place, the difference of longitude is determined in hours, which can readily be reduced to degrees by multiplying by fifteen, as 1 h. = 15 deg..

[Footnote 1: To obtain this time by observation, note the instant of first contact of the sun's limb, and also of last contact of same, and take the mean.]

APPROXIMATE EQUATION OF TIME.

_____ Date. Minutes. __ __ Jan. 1 4 3 5 5 6 7 7 9 8 12 9 15 10 18 11 21 12 25 13 31 14 Feb. 10 15 21 14 Clock 27 13 faster M'ch 4 12 than 8 11 sun. 12 10 15 9 19 8 22 7 25 6 28 5 April 1 4 4 3 7 2 11 1 15 0 19 1 24 2 30 3 May 13 4 Clock 29 3 slower. June 5 2 10 1 15 0 20 1 25 2 29 3 July 5 4 11 5 28 6 Clock Aug. 9 5 faster. 15 4 20 3 24 2 28 1 31 0 Sept. 3 1 6 2 9 3 12 4 15 5 18 6 21 7 24 8 27 9 30 10 Oct. 3 11 6 12 10 13 14 14 19 15 27 16 Clock Nov. 15 15 slower. 20 14 24 13 27 12 30 11 Dec. 2 10 5 9 7 8 9 7 11 6 13 5 16 4 18 3 20 2 22 1 24 0 26 1 28 2 Clock 30 3 faster. __ __

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THE OCELLATED PHEASANT.

The collections of the Museum of Natural History of Paris have just been enriched with a magnificent, perfectly adult specimen of a species of bird that all the scientific establishments had put down among their desiderata, and which, for twenty years past, has excited the curiosity of naturalists. This species, in fact, was known only by a few caudal feathers, of which even the origin was unknown, and which figured in the galleries of the Jardin des Plantes under the name of Argus ocellatus. This name was given by J. Verreaux, who was then assistant naturalist at the museum. It was inscribed by Prince Ch. L. Bonaparte, in his Tableaux Paralleliques de l'Ordre des Gallinaces, as Argus giganteus, and a few years later it was reproduced by Slater in his Catalogue of the Phasianidae, and by Gray is his List of the Gallinaceae. But it was not till 1871 and 1872 that Elliot, in the Annals and Magazine of Natural History, and in a splendid monograph of the Phasianidae, pointed out the peculiarities that were presented by the feathers preserved at the Museum of Paris, and published a figure of them of the natural size.

The discovery of an individual whose state of preservation leaves nothing to be desired now comes to demonstrate the correctness of Verreaux's, Bonaparte's, and Elliot's suppositions. This bird, whose tail is furnished with feathers absolutely identical with those that the museum possessed, is not a peacock, as some have asserted, nor an ordinary Argus of Malacca, nor an argus of the race that Elliot named Argus grayi, and which inhabits Borneo, but the type of a new genus of the family Phasianidae. This Gallinacean, in fact, which Mr. Maingonnat has given up to the Museum of Natural History, has not, like the common Argus of Borneo, excessively elongated secondaries; and its tail is not formed of normal rectrices, from the middle of which spring two very long feathers, a little curved and arranged like a roof; but it consists of twelve wide plane feathers, regularly tapering, and ornamented with ocellated spots, arranged along the shaft. Its head is not bare, but is adorned behind with a tuft of thread-like feathers; and, finally, its system of coloration and the proportions of the different parts of its body are not the same as in the common argus of Borneo. There is reason, then, for placing the bird, under the name of Rheinardius ocellatus, in the family Phasianidae, after the genus Argus which it connects, after a manner, with the pheasants properly so-called. The specific name ocellatus has belonged to it since 1871, and must be substituted for that of Rheinardi.

The bird measures more than two meters in length, three-fourths of which belong to the tail. The head, which is relatively small, appears to be larger than it really is, owing to the development of the piliform tuft on the occiput, this being capable of erection so as to form a crest 0.05 to 0.06 of a meter in height. The feathers of this crest are brown and white. The back and sides of the head are covered with downy feathers of a silky brown and silvery gray, and the front of the neck with piliform feathers of a ruddy brown. The upper part of the body is of a blackish tint and the under part of a reddish brown, the whole dotted with small white or cafe-au-lait spots. Analogous spots are found on the wings and tail, but on the secondaries these become elongated, and tear-like in form. On the remiges the markings are quite regularly hexagonal in shape; and on the upper coverts of the tail and on the rectrices they are accompanied with numerous ferruginous blotches, some of which are irregularly scattered over the whole surface of the vane, while others, marked in the center with a blackish spot, are disposed in series along the shaft and resemble ocelli. This similitude of marking between the rectrices and subcaudals renders the distinction between these two kinds of feathers less sharp than in many other Gallinaceans, and the more so in that two median rectrices are considerably elongated and assume exactly the aspect of tail feathers.



The true rectrices are twelve in number. They are all absolutely plane, all spread out horizontally, and they go on increasing in length from the exterior to the middle. They are quite wide at the point of insertion, increase in diameter at the middle, and afterward taper to a sharp point. Altogether they form a tail of extraordinary length and width which the bird holds slightly elevated, so as to cause it to describe a graceful curve, and the point of which touches the soil. The beak, whose upper mandible is less arched than that of the pheasants, exactly resembles that of the arguses. It is slightly inflated at the base, above the nostrils, and these latter are of an elongated-oval form. In the bird that I have before me the beak, as well as the feet and legs, is of a dark rose-color. The legs are quite long and are destitute of spurs. They terminate in front in three quite delicate toes, connected at the base by membranes, and behind in a thumb that is inserted so high that it scarcely touches the ground in walking. This magnificent bird was captured in a portion of Tonkin as yet unexplored by Europeans, in a locality named Buih-Dinh, 400 kilometers to the south of Hue.—La Nature.

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THE MAIDENHAIR TREE.

The Maidenhair tree—Gingkgo biloba—of which we give an illustration, is not only one of our most ornamental deciduous trees, but one of the most interesting. Few persons would at first sight take it to be a Conifer, more especially as it is destitute of resin; nevertheless, to that group it belongs, being closely allied to the Yew, but distinguishable by its long-stalked, fan-shaped leaves, with numerous radiating veins, as in an Adiantum. These leaves, like those of the larch but unlike most Conifers, are deciduous, turning of a pale yellow color before they fall. The tree is found in Japan and in China, but generally in the neighborhood of temples or other buildings, and is, we believe, unknown in a truly wild state. As in the case of several other trees planted in like situations, such as Cupressus funebris, Abies fortunei, A. kaempferi, Cryptomeria japonica, Sciadopitys verticillata, it is probable that the trees have been introduced from Thibet, or other unexplored districts, into China and Japan. Though now a solitary representative of its genus, the Gingkgo was well represented in the coal period, and also existed through the secondary and tertiary epochs, Professor Heer having identified kindred specimens belonging to sixty species and eight genera in fossil remains generally distributed through the northern hemisphere. Whatever inference we may draw, it is at least certain that the tree was well represented in former times, if now it be the last of its race. It was first known to Kaempfer in 1690, and described by him in 1712, and was introduced into this country in the middle of the eighteenth century. Loudon relates a curious tale as to the manner in which a French amateur became possessed of it. The Frenchman, it appears, came to England, and paid a visit to an English nurseryman, who was the possessor of five plants, raised from Japanese seeds. The hospitable Englishman entertained the Frenchman only too well. He allowed his commercial instincts to be blunted by wine, and sold to his guest the five plants for the sum of 25 guineas. Next morning, when time for reflection came, the Englishman attempted to regain one only of the plants for the same sum that the Frenchman had given for all five, but without avail. The plants were conveyed to France, where as each plant had cost about 40 crowns, ecus, the tree got the name of arbre a quarante ecus. This is the story as given by Loudon, who tells us that Andre Thouin used to relate the fact in his lectures at the Jardin des Plantes, whether as an illustration of the perfidy of Albion is not stated.

The tree is dioecious, bearing male catkins on one plant, female on another. All the female trees in Europe are believed to have originated from a tree near Geneva, of which Auguste Pyramus de Candolle secured grafts, and distributed them throughout the Continent. Nevertheless, the female tree is rarely met with, as compared with the male; but it is quite possible that a tree which generally produces male flowers only may sometimes bear female flowers only. We have no certain evidence of this in the case of the Gingkgo, but it is a common enough occurrence in other dioecious plants, and the occurrence of a fruiting specimen near Philadelphia, as recently recorded by Mr. Meehan, may possibly be attributed to this cause.

The tree of which we give a figure is growing at Broadlands, Hants, and is about 40 feet in height, with a trunk that measures 7 feet in girth at 3 feet from the ground, with a spread of branches measuring 45 feet. These dimensions have been considerably exceeded in other cases. In 1837 a tree at Purser's Cross measured 60 feet and more in height. Loudon himself had a small tree in his garden at Bayswater on which a female branch was grafted. It is to be feared that this specimen has long since perished.

We have already alluded to its deciduous character, in which it is allied to the larch. It presents another point of resemblance both to the larch and the cedar in the short spurs upon which both leaves and male catkins are borne, but these contracted branches are mingled with long extension shoots; there seems, however, no regular alternation between the short and the long shoots, at any rate the rationale of their production is not understood, though in all probability a little observation of the growing plant would soon clear the matter up.

The fruit is drupaceous, with a soft outer coat and a hard woody shell, greatly resembling that of a Cycad, both externally and internally. Whether the albumen contains the peculiar "corpuscles" common to Cycads and Conifers, we do not for certain know, though from the presence of 2 to 3 embryos in one seed, as noted by Endlicher, we presume this is the case. The interest of these corpuscles, it may be added, lies in the proof of affinity they offer between Conifers and the higher Cryptogams, such as ferns and lycopods—an affinity shown also in the peculiar venation of the Gingkgo. Conifers are in some degree links between ordinary flowering plants and the higher Cryptogams, and serve to connect in genealogical sequence groups once considered quite distinct. In germination the two fleshy cotyledons of the Gingkgo remain within the shell, leaving the three-sided plumule to pass upward; the young stem bears its leaves in threes.

We have no desire to enter further upon the botanical peculiarities of this tree; enough if we have indicated in what its peculiar interest consists. We have only to add that in gardens varieties exist some with leaves more deeply cut than usual, others with leaves nearly entire, and others with leaves of a golden-yellow color.—Gardeners' Chronicle.



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THE WOODS OF AMERICA.

A collection of woods without a parallel in the world is now being prepared for exhibition by the Directors of the American Museum of Natural History. Scattered about the third floor of the Arsenal, in Central Park, lie 394 logs, some carefully wrapped in bagging, some inclosed in rough wooden cases, and others partially sawn longitudinally, horizontally, and diagonally. These logs represent all but 26 of the varieties of trees indigenous to this country, and nearly all have a greater or less economic or commercial value. The 26 varieties needed to complete the collection will arrive before winter sets in, a number of specimens being now on their way to this city from the groves of California. Mr. S. D. Dill and a number of assistants are engaged in preparing the specimens for exhibition. The logs as they reach the workroom are wrapped in bagging and inclosed in cases, this method being used so that the bark, with its growth of lichens and delicate exfoliations, shall not be injured while the logs are in process of transportation from various parts of the country to this city. The logs are each 6 feet in length, and each is the most perfect specimen of its class that could be found by the experts employed in making the collection. With the specimens of the trees come to the museum also specimens of the foliage and the fruits and flowers of the tree. These come from all parts of the Union—from Alaska on the north to Texas on the south, from Maine on the east to California on the west—and there is not a State or Territory in the Union which has not a representative in this collection of logs. On arrival here the logs are green, and the first thing in the way of treatment after their arrival is to season them, a work requiring great care to prevent them from "checking," as it is technically called, or "season cracking," as the unscientific term the splitting of the wood in radiating lines during the seasoning process. As is well known, the sap-wood of a tree seasons much more quickly than does the heart of the wood. The prevention of this splitting is very necessary in preparing these specimens for exhibition, for when once the wood has split its value for dressing for exhibition is gone. A new plan to prevent this destruction of specimens is now being tried with some success under the direction of Prof. Bickmore, superintendent of the museum. Into the base of the log and alongside the heart a deep hole is bored with an auger. As the wood seasons this hole permits of a pressure inward and so has in many instances doubtless saved valuable specimens. One of the finest in the collection, a specimen of the persimmon tree, some two feet in diameter, has been ruined by the seasoning process. On one side there is a huge crack, extending from the top to the bottom of the log, which looks as though some amateur woodman had attempted to split it with an ax and had made a poor job of it. The great shrinking of the sap-wood of the persimmon tree makes the wood of but trifling value commercially. It also has a discouraging effect upon collectors, as it is next to impossible to cure a specimen, so that all but this one characteristic of the wood can be shown to the public in a perfect form.

Before the logs become thoroughly seasoned, or their lines of growth at all obliterated, a diagram of each is made, showing in accordance with a regular scale the thickness of the bark, the sap-wood, and the heart. There is also in this diagram a scale showing the growth of the tree during each year of its life, these yearly growths being regularly marked about the heart of the tree by move or less regular concentric circles, the width of which grows smaller and smaller as the tree grows older. In this connection attention may be called to a specimen in the collection which is considered one of the most remarkable in the world. It is not a native wood, but an importation, and the tree from which this wonderful slab is cut is commonly known as the "Pride of India." The heart of this particular tree was on the port side, and between it and the bark there is very little sap-wood, not more than an inch. On the starbord side, so to speak, the sap-wood has grown out in an abnormal manner, and one of the lines indicative of a year's growth is one and seven-eighths inches in width, the widest growth, many experts who have seen the specimen say, that was ever recorded. The diagrams referred to are to be kept for scientific uses, and the scheme of exhibition includes these diagrams as a part of the whole.

After a log has become seasoned it is carefully sawed through the center down about one-third of its length. A transverse cut is then made and the semi-cylindrical section thus severed from the log is removed. The upper end is then beveled. When a log is thus treated the inspector can see the lower two-thirds presenting exactly the same appearance it did when growing in the forest. The horizontal cut, through the sap-wood and to the center of the heart, shows the life lines of the tree, and carefully planed as are this portion, the perpendicular and the beveled sections, the grain of the wood can thus be plainly seen. That these may be made even more valuable to the architect and artisan, the right half of this planed surface will be carefully polished, and the left half left in the natural state. This portion of the scheme of treatment is entirely in the interests of architects and artisans, and it is expected by Prof. Bickmore that it will be the means of securing for some kinds of trees, essentially of American growth, and which have been virtually neglected, an important place in architecture and in ornamental wood-work, and so give a commercial value to woods that are now of comparatively little value.

Among the many curious specimens in the collection now being prepared for exhibition, one which will excite the greatest curiosity is a specimen of the honey locust, which was brought here from Missouri. The bark is covered with a growth of thorns from one to four inches in length, sharp as needles, and growing at irregular intervals. The specimen arrived here in perfect condition, but, in order that it might be transported without injury, it had to be suspended from the roof of a box car, and thus make its trip from Southern Missouri to this city without change. Another strange specimen in the novel collection is a portion of the Yucca tree, an abnormal growth of the lily family. The trunk, about 2 feet in diameter, is a spongy mass, not susceptible of treatment to which the other specimens are subjected. Its bark is an irregular stringy, knotted mass, with porcupine-quill-like leaves springing out in place of the limbs that grow from all well-regulated trees. One specimen of the yucca was sent to the museum two years ago, and though the roots and top of the tree were sawn off, shoots sprang out, and a number of the handsome flowers appeared. The tree was supposed to be dead and thoroughly seasoned by this Fall, but now, when the workmen are ready to prepare it for exhibition, it has shown new life, new shoots have appeared, and two tufts of green now decorate the otherwise dry and withered log, and the yucca promises to bloom again before the winter is over. One of the most perfect specimens of the Douglass spruce ever seen is in the collection, and is a decided curiosity. It is a recent arrival from the Rocky Mountains. Its bark, two inches or more in thickness, is perforated with holes reaching to the-sap-wood. Many of these contain acorns, or the remains of acorns, which have been stored there by provident woodpeckers, who dug the holes in the bark and there stored their winter supply of food. The oldest specimen in the collection is a section of the Picea engelmanni, a species of spruce growing in the Rocky Mountains at a considerable elevation above the sea. The specimen is 24 inches in diameter, and the concentric circles show its age to be 410 years. The wood much resembles the black spruce, and is the most valuable of the Rocky Mountain growths. A specimen of the nut pine, whose nuts are used for food by the Indians, is only 15 inches in diameter, and yet its life lines show its age to be 369 years. The largest specimen yet received is a section of the white ash, which is 46 inches in diameter and 182 years old. The next largest specimen is a section of the Platanus occidentalis, variously known in commerce as the sycamore, button-wood, or plane tree, which is 42 inches in diameter and only 171 years of age. Specimens of the redwood tree of California are now on their way to this city from the Yosemite Valley. One specimen, though a small one, measures 5 feet in diameter and shows the character of the wood. A specimen of the enormous growths of this tree was not secured because of the impossibility of transportation and the fact that there would be no room in the museum for the storage of such a specimen, for the diameter of the largest tree of the class is 45 feet and 8 inches, which represents a circumference of about 110 feet. Then, too, the Californians object to have the giant trees cut down for commercial, scientific, or any other purposes.

To accompany these specimens of the woods of America, Mr. Morris K. Jesup, who has paid all the expense incurred in the collection of specimens, is having prepared as an accompanying portion of the exhibition water color drawings representing the actual size, color, and appearance of the fruit, foliage, and flowers of the various trees. Their commercial products, as far as they can be obtained, will also be exhibited, as, for instance, in the case of the long-leaved pine, the tar, resin, and pitch, for which it is especially valued. Then, too, in an herbarium the fruits, leaves, and flowers are preserved as nearly as possible in their natural state. When the collection is ready for public view next spring it will be not only the largest, but the only complete one of its kind in the country. There is nothing like it in the world, as far as is known; certainly not in the royal museums of England, France, or Germany.

Aside from the value of the collection, in a scientific way, it is proposed to make it an adjunct to our educational system, which requires that teachers shall instruct pupils as to the materials used for food and clothing. The completeness of the exhibition will be of great assistance also to landscape gardeners, as it will enable them to lay out private and public parks so that the most striking effects of foliage may be secured. The beauty of these effects can best be seen in this country in our own Central Park, where there are more different varieties and more combinations for foliage effects than in any other area in the United States. To ascertain how these effects are obtained one now has to go to much trouble to learn the names of the trees. With this exhibition such information can be had merely by observation, for the botanical and common names of each specimen will be attached to it. It will also be of practical use in teaching the forester how to cultivate trees as he would other crops. The rapid disappearance of many valuable forest trees, with the increase in demand and decrease in supply, will tend to make the collection valuable as a curiosity in the not far distant future as representing the extinct trees of the country.—N.Y. Times.

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