But there are approximate conclusions, readily applicable to practice, at which even the unprofessional can arrive with certainty and security on a proper presentation of the prominent facts and theories concerned; and that these may be given to the public in a reliable and intelligible form, for the removal of the doubts and obscurities which have hung around the subject, is the chief object of this publication. This inquiry becomes the more important as the speed of American steamers is proverbially beyond that of any other steam vessels in the world. From the first conception of fluvial and marine steam propulsion by Fitch and Fulton, the public and the inventors themselves regarded the new application of this power with the more favor as it promised to be a means of shortening the long distances between the different parts of our own large country. And the same object has acted as a stimulus ever since to that increase of speed which has placed localities all over this country, hitherto days apart, now, probably, but as many hours. The slow trip through marshes and rivers, over hills and mountains, and by the meandering roads of the country, between New-York and Albany, once required from four to six days; but the attainment of twenty-five miles per hour in our fast river steamers has at length placed that capital within six hours of the Metropolis. And, as in this instance, so has the effort been throughout our whole country, and upon the ocean, until we have attained, both upon the rivers and the high seas, the highest speed yet known, notwithstanding the important fact that steamship building is a new and not fully developed species of enterprise in this country. We have already seen how imperatively the spirit of the age and the genius of our people demand rapid steam mails by both land and sea, and a rapid conveyance of passengers; and it would be unreasonable to suppose that if we required these for the development of our youth, they would be less necessary for the fruitful uses of manhood and maturity. It is abundantly evident that the American people are by nature and habit a progressive and unusually hurrying people; and it is not to be supposed that they will reverse this constitutional law of their nature in their attempts at ocean navigation.

To answer the question, "What is the cost of high, adequate mail speed?" requires something more than an inquiry into the quantity of fuel consumed; although this is the principal element of its cost. We must consider that the attainment and maintenance of high speed depend upon the exertion of a high power; and that,

I. High speed and power require stronger parts in every thing: in the ship's build, the machinery, the boilers, and all of the working arrangements:

II. High speed and power require a larger outlay in prime cost, in material and building, for the adequate resistance required by such power:

III. High speed and power require more frequent and costly repairs:

IV. High speed and power require more watchfulness, a more prompt action, and consequently more persons:

V. High speed and power require more fuel, more engineers, more firemen, and more coal-stokers.

1. These propositions are nearly all self-evident to every class of mind. That a high speed attained through the exertion of a high power will require stronger parts in every thing that exerts a force or resists one, is as manifest as that a force necessary to remove one ton of weight will have to be doubled to remove two tons. In the prime construction of the hull this is as requisite as in any other part. The resistance to a vessel, or the concussion against the water, at a low rate of speed, will not be very sensibly felt; but if that speed is considerably increased and the concussion made quicker without a corresponding increase in the strength of the frame and hull of the ship generally, we shall find the ship creaking, straining, and yielding to the pressure, until finally it works itself to pieces, and also disconcerts the engines, whose stability, bracing, and keeping proper place and working order depend first and essentially on the permanence and stability of the hull. If the resistance to a vessel in passing through the water increases as the square of the velocity, and if in addition to this outward thrust against the vessel it has to support the greater engine power within it, which has increased as the cube of the velocity, then the strength of the vessel must be adequate to resist without injury these two combined forces against which it has to contend.

The same increased strength is necessary also in the engines and boilers. It is admitted by the ablest engineers, and verified by practice, as will be shown in another part of this Section, that to increase the speed of a steamer from eight to ten knots per hour, it is necessary to double the power, and so on in the ratio of the cubes of the velocity. Suppose that we wish to gain these two knots advance on eight. It is evident that, if the boilers have to generate, and the engines to use twice the power, and exert twice the force, they must have also twice the strength. The boiler must be twice as strong and heavy; the various working parts of the engine must be twice as strong: the shafts, the cranks, the piston and other rods, the beams, the cylinders, the frame work, whether of wood or iron, and even the iron wheels themselves, with every thing in any way employed to use the power, overcome the resistance, and gain the speed. There is no working arrangement in any way connected with the propulsion of the ship that does not partake of this increase; every pump, every valve, every bolt connected directly or indirectly with the engine economy of the ship.

2. In the second place, seeing that much greater strength of parts is required to overcome the increased resistance, it is equally evident that this high speed and power thus require a larger outlay in every point of the prime construction of the vessel and engines by which the speed is to be attained. The hull's heavier timbers cost a higher price according to size than the direct proportion of size indicates. Large and choice timbers are difficult to get, and costly. The hull must also be strengthened to a large extra extent by heavy iron strapping and bracing, which, unlike the rest, cost in the ratio of the material used. So with the engines. The shaft, which weighs twice as much, does not cost only twice as much, but frequently three or four or five times as much. This arises not from the weight of the metal, as is evident; but from the difficulty of forging pieces that are so large. The persons engaged in the forging and finishing of the immense shafts, cranks, pistons, etc., used in our first class steamers, frequently consider that the last and largest piece is the chef d'oeuvre of the art, and that it will never be transcended, even if equalled again. They have expended all of their skill and ingenuity in the task, and have not succeeded sometimes until they have forged two or three new pieces. When a great work of this kind is done, it may be discovered in the turning, polishing, and fitting up, that it has at last a flaw, and that it will not do for the service intended. As a matter of course, it must be thrown aside and a new piece forged. This was but recently the case with one of the shafts of the "Leviathan," in England. So with the shafts of the new Collins' steamer "Adriatic." They were forged in Reading, Pennsylvania, and in addition to their enormous prime cost had to incur that of shipment from the interior of Pennsylvania to the city of New-York. In all such cases the prime cost increases immensely, and to an extent that would hardly be credited by those not practically familiar with the subject.

3. Again, high or increased power and speed require more frequent and more costly repairs. Friction arises from the pressure of two bodies moving in opposite directions, and pressure results from the exertion of power, and in the ratio of the power applied. The amount of friction, therefore, is in the ratio of the power expended and of the extra weight of parts required for that power. But the effects of friction require a higher ratio when the power is greatly multiplied, as in the case of high speed. An immensely heavy shaft exerting an unusual force is certain to greatly heat the journals and boxes, and thus wear them away far more rapidly. Also a rapid motion of heavy parts of machinery, and the necessarily severe concussions and jarrings can not fail destroying costly working parts in the engine, and necessitating heavy and expensive repairs and substitutions. An ordinary engine working at a slow and easy rate, will not require one tenth the repairs necessary if it were working up to a high power and accomplishing a high speed. With any little derangement the engines can stop and the injury can be repaired before it reaches any magnitude. But with rapid mail packets the engines must run on, and the derangement which at first is small, will amount in the end, when the voyage is completed and the mails are delivered, to a sum probably ten or twenty times as great as in the case of the vessel that stops and makes her repairs as she requires them. The exertion of a high mail power causes many costly parts to burn out from unrelieved pressure and friction, which would not be the case under other conditions. It is also nearly impossible for the best built engines in the world to make fast time without breaking some important part at every trip or two, or so cracking and injuring it from the continued strain, that a wise precaution requires its removal to make the steamer perfectly sea-worthy. Every practical man knows these difficulties, and every steamship owner estimates their importance according to the immense bills they occasion month by month, or the delays and losses which they cause unless he has expended large amounts of capital in providing other ships to take their place on such occasions of derangement.

Nor is the burning out of heavy brass, and composition, and steel pieces, or the breaking of large and troublesome parts in the engine the only source of repairs on a steamship. The boiler department is particularly fruitful in large bills of repairs, especially if it be necessary to attain a good mail speed. It stands to reason that if the whole ship can not be filled with boiler power, which with reasonably high fires, would give enough steam, then the boilers which are used must be exerted to their highest capacity, or the rapid speed can not be attained. Many suppose that the boilers may generate twice the quantity of steam without any appreciable difference in the wear and tear; but this is a decided error. For high speed, and what I mean by high speed is simply that which gives a sufficiently rapid transit to the mails, the fires must be nurtured up to their highest intensity and every pound of coal must be burned in every corner of the furnaces which will generate even an ounce of steam. This continued heat becomes too powerful for the furnaces and the boilers, and they begin to oxidize, and burn, and melt away, as would never be the case under ordinary heat. When the ship comes into port it is found that her furnaces must be "overhauled," her grate bars renewed, her braces restored, her boilers patched, sometimes all over, several of their plates taken out, thousands of rivets removed and supplied, and probably dozens of tubes also removed and replaced with new ones. But this is not all. The best boilers can not long run in this way. After six to seven years at the utmost, they must be removed from the ship altogether, and new ones must be put into their place. This is also a most expensive operation. The boilers constitute a large share of the cost of the engine power. To put a new set of boilers in one of the Collins steamers will cost about one hundred and ten thousand dollars, and this must be done every six years. The boilers of the West-India Royal Mail Steamers, which run very slowly, last on an average, six years.[A]

[A] Statement by Mr. Pitcher, builder, before the Committee of the House of Commons. Murray on the Steam Engine, p. 170, Second Edition.

But this is not all. To restore the boilers, a ship has to be torn literally almost to pieces. All of the decks in that part must be removed and lost; the frame of the ship cut to pieces; large and costly timbers removed, and altogether an expense incurred that is frightful even to the largest companies. To insure perfect safety and to gratify the wish of the public, this is generally done long before it is strictly necessary, and when the boilers are in a perfectly good condition for the working purposes of ordinary speed. But precaution and safety are among the prerequisites of the public service, and must be attained at whatever cost. On slow auxiliary freighting steamers this would be by no means necessary. But the extent and cost of these repairs on steamers far exceed any thing that would be imagined. They are supposed to be twelve per cent. per annum of the prime cost of a vessel of ordinary speed, taking the whole ship's life together at twelve years at the utmost. Atherton in his "Marine Engine Construction and Classification," page 32, says of the repairs of steam vessels doing ordinary service in Great Britain, where all such work is done much cheaper than in this country: "By the Parliamentary evidence of the highest authorities on this point, it appears to have been conclusively established, that the cost of upholding steamship machinery has of late years amounted, on the average, to about L6 per horse power per annum, being about 12 per cent. per annum, on the prime cost of the machinery, which annual outlay is but one of the grand points of current expense in which steamship proprietors are concerned." Now, if these were the repairs of the slow West-India Royal mail steamers, which ran but 200 days in the year, and that at a very moderate speed, and in the machine shops of England, where at that time (previous to 1852) wages were very low, they can not be less in this country, on rapid mail steamers, where wages and materials are very high, and where marine engineering was then in its infancy.

There are some facts on this subject which prove the positions here taken. The Collins steamers have been running but six years, and yet their repairs have amounted in all to more than the prime cost of the ships, or to about eighteen per cent. per annum. They were as well and as strongly built originally as any ships in the world, as appears from the report which Commodore M. C. Perry made to the Department regarding them, and from the fine condition of their hulls at the present time. Their depreciation with all of these repairs has not been probably above six per cent. per annum. They will, however, probably depreciate ten per cent. during the next six years, and at the age of twelve or fourteen years be unfit for service. The steamers Washington and Hermann, which had strong hulls, have been run eight years, and are now nearly worthless. Their depreciation has been at least ten per cent. The steamers Georgia and Ohio, which Commodore Perry and other superintending navy agents pronounced to be well-built and powerful steamers, (See Report Sec. Navy, 1852,) ran only five years, and were laid aside, and said to be worthless. With all of the repairs put upon these ships, which were admitted to be capable of doing first class war service, as intended, they depreciated probably seventeen per cent.; as it is hardly possible that their old iron would sell for more than fifteen per cent. of their prime cost. These steamers paid much smaller repair bills than the Collins, and were not so well constructed, or at so high a cost. American steamers do not, upon the average, last above ten years; but if they reach twelve or fourteen, they will pay a sum nearly equal to twice their cost, for repairs and substitutions. Nor is this all. The life of a steamer ends when her adaptation to profitable service ceases. She may not be rotten, but may be so slow, or of so antiquated construction, or may burn so much more fuel than more modern competitors, that she can not stand the test of competition.

4. We thus see that not only are the requisite repairs most extensive and costly, but of such magnitude as to greatly reduce the earnings of any class of steam vessels. But this is not the last costly consequence of mail speed. It requires more cautious watchfulness of the engines, the boilers, the deck, and of every possible department of the navigation, even including pilotage. It requires also more promptness and dispatch in every movement, and hence a much larger aggregate number of men. More men are necessary to keep up high fires; twice as many men are necessary to pass twice as much coal; twice as many engineers as under other circumstances are necessary for the faithful working of the engines, and any accidents and repairs which are indispensable on the ocean; and a larger number of sailors and officers is necessary to all of the prompt movements required of the mail steamer. The Havre mail steamers, the "Arago" and "Fulton," never carry less than six engineers each, although they could be run across the ocean with three under a hard working system. But this number insures the greater safety of the ship under ordinary circumstances, and is absolutely necessary in any case of accident and danger. It is the same case with the firemen. When, in a heavy storm, the fire department may be imperfectly manned, the ship has taken one of the first chances for rendering the engines inefficient, and being finally lost. And all of these extra and indispensable employees make an extra drain on the income of the ship, and add to the extreme costliness of a high adequate mail speed.

5. It is clear, then, that an adequate mail speed requires more fuel, more engineers, more firemen, more coal-stokers, and more general expense. The question of fuel is, however, alone the most important of all those affecting the attainment of high speed, and the item whose economy has been most desired and sought, both by those attempting to carry freight, and those who carry the mails and passengers. The principal points of interests concerning it are, the enormous quantity which both theory and practice show to be necessary to fast vessels; the large sum to be paid for it, and the steadily increasing price; and the paying freight room which its necessary carriage occupies. In fast steaming, the supply of coal to the furnaces frequently arrives at a point where many additional tons may be burned and yet produce no useful effect or increase of power. The draft through the furnaces and smoke stacks is so rapid and strong as to take off a vast volume of heat; and this, coupled with a large quantity of heat radiated from the various highly heated parts and surfaces, requires a consumption of fuel truly astonishing. If we reflect that at the twelve principal ports of Great Britain in the year of 1855, the tonnage entered was 6,372,301, and departed 6,426,566, equal to 12,798,867 total, and this during the war, that a large part of this was steam tonnage, and that the total imports and exports of Great Britain for 1856 were 1,600,000,000 dollars, we can somewhat appreciate the present and future uses of coal, and its inevitably large increase in price. The two hundred and seventy steamers in the British Navy, with about 50,000 aggregate horse power, consumed in 1856, according to a report made to a Committee of the "British Association for the Advancement of Science," this year, by Rear-Admiral Moorsom, 750,000 tons of coal. The difficulty and cost of mining coal, its distance from the sea-shore, and the multifarious new applications in its use among our rapidly increasing population, as well as its almost universal and increasing demand for marine purposes, all conspire to make it more costly from year to year; while, as a propelling agent, it is already beyond the reach of commercial ocean steam navigation. Coal has gone up by a steady march during the last seven years from two and a half to eight dollars per ton, which may now be regarded as a fair average price along our Atlantic seaboard. And that we may see more clearly how essentially the speed and cost of steam marine navigation depend upon the simple question of fuel alone, to say nothing further of the impeding causes heretofore mentioned, I will now present a few inquiries concerning

THE NATURAL LAWS OF RESISTANCE, POWER, AND SPEED,

WITH TABLES OF THE SAME.

The resistance to bodies moving through the water increases as the square of the velocity; and the power, or coal, necessary to produce speed varies or increases as the cube of the velocity. This is a law founded in nature, and verified by facts and universal experience. Its enunciation is at first startling to those who have not reflected on the subject, and who as a general thing suppose that, if a vessel will run 8 miles per hour on a given quantity of coal, she ought to run 16 miles per hour on double that quantity. I think that it may be safely asserted that in all cases of high speed, and ordinary dynamic or working efficiency in the ship, the resistance increases more rapidly than as the squares. The rationale of the law is this: the power necessary to overcome the resistance of the water at the vessel's bow and the friction increases as the square; again, the power necessary to overcome the natural inertia of the vessel and set it in motion, increases this again as the square of the velocity, and the two together constitute the aggregate resistance which makes it necessary that the power for increasing a vessel's speed shall increase as the cube of the velocity. But whatever the rationale, the law itself is an admitted fact by all theoretical engineers, and is proven in practice by all steamships. In evidence of this, I will give the following opinions.

In his treatise on "The Marine Engine," Mr. Robert Murray, who is a member of the Board of Trade in Southampton, England, says in speaking of the "Natural law regulating the speed of a steamer," page 104: "These results chiefly depend upon the natural law that the power expended in propelling a steamship through the water varies as the cube of the velocity. This law is modified by the retarding effect of the increased resisting surface, consequent upon the weight of the engines and fuel, so that the horse power increases in a somewhat higher ratio than that named." It must be understood that when he speaks of power, horse power, etc., it is simply another form of representing the quantity of coal burned; as the power is in the direct ratio of the quantity of fuel.

Bourne, the great Scotch writer upon the Screw Propeller, in his large volume published by Longmans, London, page 145, says, in concluding a sentence on the expensiveness of vessels: "Since it is known that the resistance of vessels increases more rapidly than the square of the velocity in the case of considerable speeds."

Again, at page 236, on "the resistance of bodies moving through the water," he says: "In the case of very sharp vessels, the resistance appears to increase nearly as the square of the velocity, but in case of vessels of the ordinary amount of sharpness the resistance increases more rapidly than the square of the velocity."

Again, on page 231, in speaking of the folly of a company attempting to run steamers sufficiently rapidly for the mails at the price paid for them, he says: "At the same time an increased rate of speed has to be maintained, which is, of course, tantamount to a further reduction of the payment. In fact, their position upon the Red Sea line is now this, that they would be better without the mails than with them, as the mere expense of the increased quantity of fuel necessary to realize the increased speed which they have undertaken to maintain, will swallow up the whole of the Government subvention. To increase the speed of a vessel from 8 to 10 knots it is necessary that the engine power should be doubled." This work of Mr. Bourne is now the standard of authority on the subject of which he treats, the world over.

Again, Mr. James R. Napier, of London, known as one of the largest and most skilled engine-builders in Great Britain, in the discussion of the dynamic efficiency of steamships in the proceedings of the "British Association" in 1856, page 436, says: "The power in similar vessels, I here take for granted, at present varies as the cube of the velocity." The power simply represents the coal; in fact, it is the coal.

Mr. Charles Atherton, the able and distinguished Chief Engineer of Her Majesty's Royal Dock Yard, at Woolwich, has published a volume, called "Steamship Capability," a smaller volume on "Marine Engine Classification," and several elaborate papers for the British Association, the Society of Arts, London, the Association of Civil Engineers, and the Artisans' Journal, for the purpose of properly exposing the high cost of steam freight transport as based on the law above noticed, and the ruinous expense of running certain classes of vessels of an inferior dynamic efficiency. When but a few weeks since in London, I asked the Editor of the "Artisan," if any engineer in England disputed the laws relative to power, on which Mr. Atherton based his arguments. He replied that he had never heard of one who did. I asked Mr. Atherton myself, if in the case of the newest and most improved steamers, with the best possible models for speed, he had ever found any defect in the law of, the resistance as the squares, and the power as the cubes of the velocity. He replied that he had not; and that he regarded the law as founded in nature, and had everywhere seen it verified in practice in the many experiments which it was his duty to conduct with steam vessels in and out of the Royal Navy. I think, therefore, that with all of these high authorities, the doctrine will be admitted as a law of power and speed, and consequently of the consumption of coal and the high cost of running steamers at mail speeds.

It is not my purpose here to discuss this law, or treat generally or specially of the theory of steam navigation. It will suffice that I point out clearly its existence and the prominent methods of its application only, as these are necessary to the general deduction which I propose making, that rapid steamships can not support themselves on their own receipts. The general reader can pass over these formulae to p. 69, and look at their results.

I. TO FIND THE CONSUMPTION OF FUEL NECESSARY TO INCREASE THE SPEED OF A STEAMER.

Suppose that a steamer running eight miles per hour consumes forty tons of coal per day: how much coal will she consume per day at nine miles per hour? The calculation is as follows:

8^3 : 9^3 :: 40 : required consumption, which is, 56.95 tons. Here the speed has increased 12-1/2 per cent., while the quantity of fuel consumed increased 42-1/2 per cent.

Suppose, again, that we wish to increase the speed from 8 to 10, and from 8 to 16 miles per hour. The formula stands the same, thus:

Miles. Miles. Tons Coal. Tons Coal. 8^3 : 10^3 :: 40 : x, = 78.1 8^3 : 16^3 :: 40 : x, = 320.

II. TO FIND THE SPEED CORRESPONDING TO A DIMINISHED CONSUMPTION OF FUEL.

Murray has given some convenient formulae, which I will here adopt. Suppose a vessel of 500 horse power run 12 knots per hour on 40 tons coal per day: what will be the speed if she burn only 30 tons per day? Thus:

40 : 30 :: 12^3 : V^3 (or cube of the required velocity,) Or, reduced, 4 : 3 :: 1728 : V^3, Equation, 3 x 1728 = 5184 = 4V^3, Or, 5184/4 = Cube root of 1296 = 10.902 knots = V, required velocity.

Thus, we reduce the quantity of coal one fourth, but the speed is reduced but little above one twelfth.

III. RELATION BETWEEN THE CONSUMPTION OF FUEL, AND THE LENGTH AND VELOCITY OF VOYAGE.

The consumption of fuel on two or more given voyages will vary as the square of the velocity multiplied into the distance travelled. Thus, during a voyage of 1200 miles, average speed 10 knots, the consumption of coal is 150 tons: we wish to know the consumption for 1800 miles at 8 knots. Thus:

150 tons : C required Consumption :: 10^2 knots x 1200 miles : 8^2, Knots x 1800 miles. Then, C x 100 x 1200 = 150 x 64 x 1800,* Or, C x 120,000 = 17,280,000 Reduced to C = 1728/12 = 144 tons consumption.

Suppose, again, that we wish to know the rate of speed for 1800 miles, if the coals used be the same as on another voyage of 1200 miles, with 150 tons coal, and ten knots speed:

We substitute former consumption, 150 tons for C, as in the equation above, marked *, and V^2 (square of the required velocity) for 64, and have,

150 x 100 x 1200 = 150 x V^2 x 1800, Or, 120,000 = 1800V^2, Reduced, 1200/18 = V^2, And V = square root of 66.66 = 8.15 knots.

From the foregoing easily intelligible formulae we can ascertain with approximate certainty the large quantity of coal necessary to increase speed, the large saving of coal in reducing speed, as well as the means of accommodating the fuel to the voyage, or the voyage to the fuel. It is not necessary here to study very closely the economy of fuel, as this is a question affecting the transport of freight alone. When the mails are to be transported, economy of fuel is not the object desired, but speed; and, consequently, we must submit to extravagance of fuel. This large expenditure of coal is not necessary in the case of freights, as they may be transported slowly, and, consequently, cheaply. But one of the principal reasons for rapid transport of the mails is that they may largely anticipate freights in their time of arrival, and consequently control their movements.

I recently had an excellent opportunity of testing the large quantity of fuel saved on a slight reduction of the speed, and give it as illustrative of the law advanced. We were on the United States Mail steamer "Fulton," Captain Wotton, and running at 13 miles per hour. Some of the tubes became unfit for use in one of the boilers, and the fires were extinguished and the steam and water drawn off from this boiler, leaving the other one, of the same size, to propel the ship. An intelligent gentleman who happened to know that we were using only one boiler, and consequently, but half the power, remarked to me that it was very strange that the ship was still going about eleven miles per hour, without any sail. He said: "It is strange, sir; two boilers of equal size drove us thirteen miles per hour; and here now but one boiler drives us nearly eleven miles, or nearly as fast; when common-sense teaches that the one boiler would drive us only six and a half miles per hour. How is that?" I then explained to him very clearly the natural law relative to power and speed, (See Rule II., page 68,) which he at once comprehended and admitted, but with the remark: "Indeed, sir, I would have testified that she ought with one boiler to have gone at only half the speed; or that going at six miles with one boiler, she would go twelve with two."

As it will be interesting to the general reader to examine the details of the increased consumption of fuel at increased rates of speed, I present the following elaborate table recently prepared by Mr. Atherton for his new edition of "Steamship Capability," according to the formula above noticed, and the performance of the best type of vessel in the Royal Navy, the steamer "Rattler." Mr. A. found a higher efficiency in this vessel per horse power than any other in the Navy, and consequently based the consumption of coal in the table on the assumption that the mail and passenger vessels generally should be of as good contractive type as "Rattler." I shall present also another table showing a much larger consumption of fuel by an inferior type of vessel. I use these tables because they are thoroughly correct, and quite as perfect as any that I could construct on the same formula; and because they carry with them the weight of probably the highest authority in Great Britain.

COAL TABLE: No. I.

Displacement,[B] Speed, and Fuel consumed per Day, for Mail, Passenger, and Freight Steamers, whose locomotive performance is equal to that of the best class of ocean steam vessels; assuming the consumption of fuel to be 4-1/2 lbs. per indicated horse power per hour, equal to 33,000 lbs. raised one foot in one minute. The quantity consumed is expressed in tons per day of 24 hours.

[B] Displacement refers to the number of cubic feet of water displaced by the hull; allowing thirty-five cubic feet to the ton.

KEY: A: SHIP'S DISPLACEMENT.

-+ + + + + + + + + + + + + + + SPEED PER HOUR. NAUTICAL MILES. A + + + + + + + + + + + + + + + 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 -+ + + + + + + + + + + + + + + TONS. TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS -+ + + + + + + + + + + + + + + 100 1.04 1.65 2.47 3.51 4.82 6.41 8.32 10.6 13.2 16.3 19.7 23.7 28.1 33.0 38.5 125 1.20 1.92 2.86 4.07 5.59 7.44 9.66 12.3 15.3 18.9 22.9 27.5 32.6 38.3 44.7 150 1.36 2.16 3.23 4.60 6.31 8.40 10.9 13.9 17.3 21.3 25.9 31.0 36.8 43.3 50.5 175 1.51 2.40 3.58 5.10 7.00 9.31 12.1 15.4 19.2 23.6 28.7 34.4 40.8 48.0 56.0 200 1.65 2.62 3.91 5.57 7.65 10.2 13.2 16.8 21.0 25.8 31.3 37.6 44.6 52.4 61.2 250 1.92 3.04 4.54 6.47 8.87 11.8 15.3 19.5 24.3 29.9 36.3 43.6 51.7 60.9 71.0 300 2.25 3.44 5.13 7.30 10.0 13.3 17.3 22.0 27.5 33.8 41.0 49.2 58.4 68.7 80.1 350 2.40 3.81 5.68 8.09 11.1 14.8 19.2 24.4 30.5 37.5 45.5 54.5 64.7 76.2 88.8 400 2.62 4.16 6.21 8.85 12.1 16.2 21.0 26.7 33.3 41.0 49.7 59.6 70.8 83.3 97.1 450 2.84 4.50 6.72 9.57 13.1 17.5 22.7 28.8 36.0 44.3 53.8 64.5 76.6 90.1 105 500 3.04 4.83 7.21 10.3 14.1 18.7 24.3 30.9 38.6 47.5 57.7 69.2 82.1 96.6 113 600 3.43 5.46 8.14 11.6 15.9 21.2 27.5 34.9 43.6 53.7 65.1 78.1 92.8 109 127 700 3.81 6.05 9.02 12.8 17.6 23.5 30.4 38.7 48.4 59.5 72.2 86.6 103 121 141 800 4.16 6.61 9.87 14.0 19.3 25.6 33.3 42.3 52.9 65.0 78.9 94.6 112 132 154 900 4.50 7.15 10.7 15.2 20.8 27.7 36.0 45.8 57.2 70.4 85.4 102 122 143 167 1000 4.83 7.67 11.4 16.3 22.4 29.8 38.6 49.1 61.3 75.5 91.6 110 130 153 179 1250 5.60 8.90 13.3 18.9 26.0 34.5 44.8 57.0 71.2 87.6 106 127 151 178 208 1500 6.33 10.0 15.0 21.4 29.3 39.0 50.6 64.4 80.4 98.9 120 144 171 201 234 1750 7.01 11.1 16.6 23.7 32.5 43.2 56.1 71.3 89.1 110 133 159 189 223 260 2000 7.66 12.2 18.2 25.9 35.5 47.3 61.3 77.9 97.4 120 145 174 207 243 284 2500 8.89 14.1 21.1 30.0 41.2 54.8 71.2 90.5 113 139 169 202 240 283 329 3000 10.0 16.0 23.8 33.9 46.5 61.9 80.4 102 128 157 191 228 271 319 372 3500 11.1 17.7 26.1 37.6 51.5 68.6 89.0 113 141 174 211 253 301 354 412 4000 12.2 19.3 28.8 41.1 56.3 75.0 97.3 124 155 190 231 277 329 386 451 5000 14.1 22.4 33.5 47.7 65.4 87.0 113 144 179 221 268 321 381 448 523 6000 15.9 25.3 37.8 53.8 73.8 98.3 128 162 203 249 302 363 431 506 591 7000 17.7 28.1 41.9 59.6 81.8 109 141 180 224 276 335 402 477 501 654 8000 19.3 30.7 45.8 65.2 89.4 119 155 196 245 302 366 439 522 613 715 9000 20.9 33.2 49.5 70.5 96.7 129 167 215 265 327 396 475 564 663 774 10000 22.4 35.6 53.1 75.6 104 138 179 228 285 350 425 510 605 712 830 12500 26.0 41.3 61.7 87.8 120 160 208 265 330 406 493 592 702 826 963 15000 29.4 46.6 69.6 99.1 136 181 235 299 373 459 557 668 793 933 1088 20000 35.6 56.5 84.4 120 165 219 285 362 452 556 675 809 961 1130 1318 25000 41.3 65.6 97.9 139 191 254 330 420 525 645 783 939 1115 1311 1529 30000 46.6 74.0 111 157 216 287 373 474 592 728 884 1060 1258 1480 1727 -+ + + + + + + + + + + + + + +

By the inspection of this table we can see in condensed form the coal-cost of any speed as high as twenty miles per hour, and for any size of vessel from one hundred tons to thirty thousand tons. Let us find in the left hand column a vessel of 2,500 tons displacement. Pursuing the line along to the right we find in the second column 8.89 tons of coal, which a steamer of this displacement would burn in 24 hours, if running, as indicated at the head of the column, 6 Nautical miles per hour.

In the next column, under the head of 7 Nautical miles per hour, we find that she would burn in one day 14.1 tons; or one and a half times as much coal to gain one sixth more speed:

Again, at 8 miles per hour she burns 21.1 tons; nearly three times as much as at six miles:

At 9 miles she burns 30 tons: above twice as much as at 7, and nearly four times as much as at 6, although the speed is but half doubled:

At 10 miles per hour she burns 41.2 tons; about twice as much as at 8 miles, although the speed is increased only one fourth. At 10 she burns 34 per cent. more than at 9, although the increase of speed is only eleven per cent. (See pages 67 and 68):

At 11 miles per hour she will burn 54.8 or 55 tons; nearly three times as much as at 8 miles per hour, and six times as much as at 6 miles per hour:

At 12 miles per hour she will burn 71.2; about thirty per cent. more than at eleven miles per hour, although gaining but 9 per cent. in speed; nearly twice as much as at ten miles per hour, three and a half times as much as at 8, five times as much as at 7, and above eight times as much as at 6 miles per hour. It is here seen that to double the speed the consumption of fuel has increased eight-fold, which verifies my statements hitherto made on this subject. We have already seen that to gain two miles of speed on any stated speed, it was necessary to double the quantity of fuel used.

At 13 miles per hour she burns 90.5 tons. This is burning two and a fourth times as much coal as if she ran only 10 miles per hour. Now, at this speed, the steamer will reach Southampton or Liverpool in 10 days and 6 hours, which is equivalent to 10 days and 12 hours burning fuel, allowing six hours for heating and starting, and which would make an aggregate consumption of 950 tons of coal for the passage of this steamer of 2,500 displacement or probably 3,000 tons register.

At 14 miles per hour she burns 113 tons. This is nearly three times as much as 10 miles per hour. At this speed the steamer would reach Southampton or Liverpool in 9 days, 12 hours, and 30 minutes, supposing the distance to be 3,200 miles from New-York, or say 9 days 18-1/2 hours coal-burning time, and would consume an aggregate of 1,104-1/2 tons. As this is but little above the distance from New-York to Southampton, and under that from Panama to California, and about the tonnage of the steamers running, the time being within eleven days generally, it will be seen how large is the cost of running the steamers of the Pacific Mail Steamship Company, those on the European routes, and also those between New-York and Aspinwall. As the route of the Havre and Bremen steamers is much longer, they are compelled to run slightly slower, or they would be filled up with their own fuel and power. Taking a Collins steamer of 3,000 tons, which we find in the line below, and we see that in running 14 miles per hour as they have frequently done, the consumption would be 128 tons per day, or 1,252 tons for the passage. And yet, one of those steamers could make 12 miles per hour on 80.4 tons per day, or at 11 miles per hour on 61.9, or less than half that used at 14. But pursuing this table we see that,

At 15 miles per hour she would burn 139 tons, or three and a half times as much as at 10 miles.

At 16 miles per hour she would burn 169 tons, or precisely eight times as much as at 8 miles per hour. Here again doubling the speed is found to be an enormous expense.

At 17 miles per hour she burns 202 tons per day.

At 18 miles per hour the consumption is 240 tons per day.

At 19 miles per hour she burns 283 tons coal per day; and

At 20 miles per hour she burns 329 tons per day. At 20 miles per hour she would run 480 miles per day, a thing as yet wholly unheard of, and would consume on the voyage of 6 days and 16 hours, say 6 days and 22 hours, 2,276 tons of coal. It would be clearly impossible for her to carry her own fuel; as the immense boiler and engine power necessary to secure this speed would of itself fill a ship of this size, to say nothing of the fuel which also would nearly fill it. Then, we may never expect any such ship to attain any such speed as seventeen, eighteen, or twenty miles per hour on so long a voyage without recoaling.

Seeing thus the enormous increase in the consumption of fuel for a moderate increase in the speed, we are enabled the better to appreciate the large expense incurred in running ocean steamers sufficiently rapidly for successful mail and passenger purposes. We will further pursue these inquiries by examining in this table the consumption for vessels of 6,000 tons, which would make the displacement of the ship nearly 5,000 tons, such as the "Adriatic," the "Vanderbilt," and the "Niagara." It appears that at 8 miles per hour they would consume 33 tons per day; at 10 miles, 65 tons; at 12 miles, 113 tons; at 13 miles, 144 tons; at 14 miles, 179 tons; at 15 miles, 221 tons; and at 16 miles, 268 tons per day. This is supposing this speed to be maintained on an average across the ocean, in all kinds of weather, which this size of steamer could not do without more engine and boiler power than any of them have. With such additional power the ships noticed would have scarcely any available room for freight or any thing else. One thing is very clear from this table, that when steamers run at very moderately slow rates of speed, their consumption of fuel is very small; and that when they leave this low freighting speed, for that of the necessarily rapid mails and passengers, the consumption increases to an extent and with a rapidity that would seem almost incredible at first view.

COAL TABLE: No. II.

The following coal table is constructed in all respects as the preceding, but for a lower type of vessels, or those whose coefficient of Dynamic performance is inferior to that upon which the previous table is estimated. As a consequence, this style of vessel requires more fuel.

KEY: A: SHIP'S DISPLACEMENT.

-+ + + + + + + + + + + + + + + SPEED PER HOUR. NAUTICAL MILES. A + + + + + + + + + + + + + + + 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 -+ + + + + + + + + + + + + + + TONS. TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS TONS -+ + + + + + + + + + + + + + + 500 3.95 6.28 9.37 13.4 18.3 24.3 31.6 40.1 50.2 61.7 75.0 89.9 106 125 147 600 4.46 7.10 10.6 15.1 20.6 27.5 35.7 45.3 56.6 69.8 84.6 101 120 141 165 700 4.95 7.86 11.7 16.6 22.8 30.5 39.5 50.3 62.9 77.3 93.8 112 134 157 183 800 5.41 8.59 12.8 18.2 25.1 33.3 43.3 55.0 68.7 84.5 102 123 145 171 200 900 5.85 9.29 13.9 19.7 27.0 36.0 46.8 59.5 74.3 91.5 111 132 158 186 217 1000 6.28 9.97 14.8 21.2 29.1 38.7 50.1 63.8 79.7 98.1 119 143 169 199 232 1250 7.28 11.5 17.3 24.5 33.8 44.8 58.2 74.1 92.5 114 137 165 196 231 270 1500 8.23 13.0 19.5 27.8 38.1 50.7 65.7 83.7 104 128 156 187 222 261 304 1750 9.11 14.4 21.5 30.8 42.2 56.1 72.9 92.7 115 143 173 206 245 290 338 2000 9.95 15.8 23.6 33.6 46.1 61.5 79.7 101 126 159 188 226 269 316 369 2500 11.5 18.3 27.4 39.0 53.5 71.2 92.5 117 147 180 219 262 312 368 427 3000 13.0 20.8 30.9 44.0 60.4 80.4 104 132 166 204 248 296 352 414 483 3500 14.4 23.0 34.3 48.8 66.9 89.1 115 147 183 226 274 329 391 460 535 4000 15.8 25.1 37.4 53.4 73.2 97.5 126 161 201 247 300 360 427 501 586 5000 18.3 29.1 43.5 62.0 85.0 113 147 187 232 287 348 417 495 582 679 6000 20.6 32.9 49.1 69.9 95.9 127 166 210 264 323 392 472 560 657 768 10000 29.1 46.2 69.0 98.2 135 179 232 296 370 455 552 663 786 925 1079 -+ + + + + + + + + + + + + + +

FREIGHT TABLE: No. III.

Showing the mutual relation of Displacement, Power, Speed, Consumption of Coal, and capacity for Cargo of vessels of progressively increasing magnitude up to nearly 30,000 tons of Deep-draught Displacement, employed on a passage of 3,250 nautical miles, without recoaling: showing also the prime cost Expenses per ton of Cargo conveyed.

KEY: A: Mean or Mid-passage Displacement. B: Speed. C: POWER. Nominal H. P. D: POWER. Indicated h. p. E: Assumed weight of Hull and Engines. F: PASSAGE 3,250 N. M. DIRECT. Time. G: PASSAGE 3,250 N. M. DIRECT. Coal. H: PASSAGE 3,250 N. M. DIRECT. Cargo. I: PASSAGE 3,250 N. M. DIRECT. Deep Displacement. J: PASSAGE 3,250 N. M. DIRECT. Expenses per Ton of Cargo.

+ -+ -+ -+ + + -+ + + A B C D E F G H I J Tons. N. M. H. P. h. p. TONS. D. H. TONS. TONS. TONS. L S. D. + -+ -+ -+ + + -+ + + { 8 109 436 1109 16.22 369 1209 2684 2 1 10 { 9 155 620 1155 15. 1 466 1112 2733 2 7 8 2,500 { 10 213 852 1213 13.13 577 999 2788 2 16 11 { 11 284 1136 1284 12. 7 699 867 2849 3 11 3 { 12 368 1472 1368 11. 7 830 717 2915 4 14 5 { 8 172 688 2172 16.22 582 2537 5291 1 16 1 { 9 245 980 2245 15. 1 737 2386 5368 1 19 7 5,000 { 10 336 1344 2336 13.13 882 2223 5441 2 4 1 { 11 448 1792 2448 12. 7 1103 2000 5551 2 13 1 { 12 581 2324 2581 11. 7 1311 1763 5655 3 5 1 { 8 276 1104 4276 16.22 934 5257 10467 1 12 3 { 9 388 1552 4388 15. 1 1168 5028 10584 1 13 10 { 10 536 2144 4536 13.13 1407 4760 10703 1 16 9 10,000 { 11 712 2848 4712 12. 7 1753 4411 10876 2 2 1 { 12 928 3712 4928 11. 7 2094 4025 11047 2 9 4 { 13 1180 4720 5180 10.10 2458 3591 11229 2 19 5 { 14 1472 5888 5472 9.16 2848 3104 11424 3 14 3 { 8 436 1744 8436 16.22 1476 10826 20738 1 9 0 { 9 620 2480 8620 15. 1 1866 10447 20933 1 9 11 { 10 852 3408 8852 13.13 2236 10030 21118 1 11 4 20,000 { 11 1136 4544 9136 12. 7 2797 9466 21398 1 14 9 { 12 1472 5888 9472 11. 7 3322 8867 21661 1 19 1 { 13 1872 7488 9872 10.10 3900 8178 21950 2 4 11 { 14 2340 9360 10340 9.16 4528 7396 22264 2 13 1 + -+ -+ -+ + + -+ + +

Mr. Atherton gives this table, which shows the following facts:

That, as the various sized vessels named, increase in speed from 8 to 12, or from 8 to 14 miles per hour, their horse power, as well consequently as their coal, increases:

That, as the speed increases, so does the weight of the hull and engines:

That, as the speed increases, with the consequent increased coal and engine weight, the cargo decreases: and

That, as the speed increases, with the other necessary conditions noticed, the expense per ton of cargo also increases in a rapid ratio. In the four cross columns ships of different sizes are considered; of 2,500, 5,000, 10,000, and 20,000 tons. There is also given the working or indicated horse power, and the nominal horse-power, or that of 33,000 lbs. raised a foot in a minute, which is the general basis of making contracts. It is a fact, however, that engines generally work up to three or four times their nominal horse power; so that the word horse power has no positive or useful meaning. Vessels called one hundred nominal horse-power have been known to work up to six hundred.

Let us take a ship of 5,000 tons. We find that at 8 miles per hour the horse power is 436; but at 12 miles it is 1,472, nearly four times as great. At 13 miles, it would be nearly 1800 horse, and at 14 it would be above 2100. So, also, with the weight of engines, boilers, etc. At 8 miles per hour they would weigh 1,109 tons; but at 12 they would have to weigh, to be large and strong enough, 1,368 tons. At 14 miles, they would weigh nearly 1,600 tons.

Now, see the columns "cargo" and "coal," and observe how rapidly that of coal increases, while that of cargo decreases in the inverse ratio of the coal, the engine, the boiler, and the hull weight combined. The cargo has come from 1,209 down to 717 tons; and if the speed were increased to 13 or 14 miles per hour, the cargo would be so reduced as to be unworthy of notice.

The next column shows how much greater the quantity of water displaced as the speed increases. This extra displacement requires extra power.

In the last column it is observable how rapidly the speed enhances the cost price of transporting cargo. At 13 miles per hour the cost would be about six pounds sterling per ton, and at 14 knots speed it would be higher than was ever paid a steamer in the most flush periods of even the best qualities of freights. Freights were about L8 per ton on the Cunard line before the establishment of the Collins; but they soon came down, and are not now L3, or $15, on an average. So with passage. The "Great Western" charged L45, the "British Queen" L50; the Cunarders, until the Collins competition, L40, 19s. The Collins steamers put the price down to L35, and have since reduced it to L30 homeward, and L24 outward. This is but little above half the fare of the Great Western, and something over two thirds of that formerly charged by the Cunard line. The Report to the House of Commons "on Steam Communications with India," No. 372 of 1851, second volume, page 395, says, that the average speed of the Cunard line was 10.443 knots, of the Collins line 11 knots, and of the Havre and Bremen lines 9.875 knots per hour. The Collins line had then just started, and has since made the average passages one and a half days quicker than those of the Cunard line. This being the case, it is easy to estimate the gains of a steamer at such rates, when this column shows us that at 12 miles speed per hour and an average trip of 11 days, the actual prime cost of moving the freight is much above that which is received for it. It is therefore taken in small quantities only to assist in paying the running expenses of the steamer.

This table shows another thing very conclusively, that large ships running the same number of miles per hour, run cheaper and transport freight more cheaply than smaller vessels. It presupposes, however, that they go full both ways. The engine power and general outlay do not increase as rapidly as the tonnage of the vessel and her capacity for carrying. While a ship 2,500 tons at 12 miles per hour on a passage of 3,250 miles would make the cost per ton for the transportation of freight $22.75, one of 20,000 tons, under the same conditions would reduce it to $9 per ton. Yet it is hardly probable that we shall ever profitably employ steamers of over 10,000 tons tonnage in the passenger, mail, and freight business.

Again, a ship of 2,500 at 12 miles, running 6,500 miles could not transport cargo at less than $115; one of 5,000 tons would transport it at $52; one of 10,000 tons would transport it at $33 per ton; and one of 20,000 tons burthen, as for instance the "Leviathan," would transport it at $24 per ton. And while none of the three first named sizes of vessels would transport it 12,500 miles, the one of 20,000 tons, running 12 miles per hour, would transport it at $80 per ton; and running 14 miles per hours, at $430 per ton. Two things must, however, not be forgotten in this; that the ship to do this must always run entirely full and have no waste room; and that these prices are comparisons between different steamers, and not with sailing vessels, which, running much more slowly and with but little expense, transport the freight far more cheaply.

The following table will set forth very clearly in a summary view, the Time, Horse-power, Coal, and Cargo for a steamer of good average quality running on passages of 1,000 miles, 2,000 miles, and 3,000 miles, and at a speed varying from 6 to 18 miles per hour. It will be observed that a steamer of 3,000 tons can not take power and coal enough to run on a 2,000 miles passage above 17 knots per hour, and that one of 3,000 tons also can not run on a 3,000 miles passage at a speed above 16 knots per hour. Observe the small quantity of cargo and the large quantity of coal for a steamer of 3,000 tons on a 3,000 miles passage at 16 miles per hour.

COAL AND CARGO TABLE: No. IV.

Calculated for the mean Displacement of 3,000 Tons.

KEY: A: SPEED—PER HOUR. B: HORSE-POWER. C: WEIGHT OF HULL AND ENGINES. D: PASSAGE 1,000 NAUTICAL MILES. Time. E: PASSAGE 1,000 NAUTICAL MILES. Coal. F: PASSAGE 1,000 NAUTICAL MILES. Cargo. G: PASSAGE 2,000 NAUTICAL MILES. Time. H: PASSAGE 2,000 NAUTICAL MILES. Coal. I: PASSAGE 2,000 NAUTICAL MILES. Cargo. J: PASSAGE 3,000 NAUTICAL MILES. Time. K: PASSAGE 3,000 NAUTICAL MILES. Coal. L: PASSAGE 3,000 NAUTICAL MILES. Cargo.

-+ -+ -+ -+ + + -+ + + -+ + A B C D E F G H I J K L N. M. H. P. TONS. D. H. TONS TONS D. H. TONS TONS D. H. TONS TONS -+ -+ -+ -+ + + -+ + + -+ + 6 52 1252 6.23 72 1711 13.21 144 1675 20.20 216 1639 7 83 1283 5.23 98 1667 11.22 197 1617 17.21 296 1568 8 123 1323 5. 5 128 1612 10.10 256 1548 15.15 384 1484 9 175 1375 4.15 162 1543 9. 6 324 1462 13.21 486 1381 10 241 1441 4. 4 200 1458 8. 8 401 1358 12.12 602 1257 11 320 1520 3.19 242 1358 7.14 484 1237 11. 9 727 1116 12 416 1616 3.11 288 1239 6.23 577 1095 10.10 866 950 13 529 1729 3. 5 339 1100 6.10 678 931 9.15 1017 761 14 661 1861 2.23 393 942 5.23 786 745 8.22 1180 548 15 813 2013 2.19 451 761 5.13 903 535 8. 8 1355 309 16 987 2187 2.14 514 555 5. 5 1028 298 7.19 1542 41 17 1183 2383 2.11 580 327 4.22 1160 37 18 1405 2605 2. 8 650 69 19 1652 2852 20 1927 3127 -+ -+ -+ -+ + + -+ + + -+ +

I will close this long chapter, in which I have endeavored to give a clear, comprehensible, and faithful idea of the cost of running ocean mail, freight, and passenger steamers, by an extract from that very able and faithful work, "Steamship Capability." As a summing up of the various laws and facts concerning the consumption of fuel, weight and power of engines, speed of ships, and their capacity to do business, Mr. Atherton says, page 55: "Now suppose, for example, that the passage be 1,000 miles, and that, for brevity, we confine our remarks to the engine department only; which, indeed, will be the department of expense, chiefly affected by variations in the rate of speed. It appears that the vessel of 5,000 tons' mean displacement, if fitted to run at the speed of EIGHT NAUTICAL MILES per hour, will require 172 H.P., and a cargo of 2,738 tons will be conveyed 1,000 miles in five days five hours; being equivalent to one day's employment of 33/100 H.P. per ton of goods.

"If fitted to run at TEN NAUTICAL MILES an hour, the vessel will require 336 H.P., the cargo will be reduced to 2,524 tons, and the time to four days four hours; being equivalent to one day's employment of 55/100 H.P. per ton of goods nearly.

"If fitted to run at TWELVE NAUTICAL MILES an hour, the vessel will require 581 H.P., the cargo will be reduced to 2,217 tons, and the time to three days eleven hours; being equivalent to one day's employment of 91/100 H.P. per ton of goods.

"If fitted to run at FOURTEEN MILES an hour, the vessel will require 923 H.P., the cargo will be reduced to 1,802 tons, and the time to two days twenty-three hours; being equivalent to one day's employment of 1-52/100 H.P. per ton of goods.

"If fitted to run at SIXTEEN MILES per hour, the vessel will require 1,377 H.P., the cargo will be reduced to 1,264 tons, and the time to two days fourteen hours; being equivalent to one day's employment of 2-86/100 H.P. per ton of goods.

"If fitted to run at EIGHTEEN MILES per hour, the vessel will require 1,961 H.P., the cargo will be reduced to 585 tons, and the time to two days eight hours; being equivalent to one day's employment of 7-75/100 H.P., per ton of goods.

"And if fitted to run at TWENTY MILES per hour, there will be no displacement available for mercantile cargo.

"Assuming, now, that the COST per ton of goods will be in proportion to the amount of power and tonnage employed to do the work, it appears that the cost per ton of goods of performing this passage of 1,000 miles, at the respective speeds of 8, 10, 12, 14, 16, and 18 miles, will be proportional to the numbers—33/100, 55/100, 91/100, 1-52/100, 2-86/100, and 7-75/100, which are proportional to the numbers 33, 55, 91, 152, 286, and 775, or nearly as 1, 2, 3, 5, 9, and 23.

"Hence it appears, that in the case of the ONE THOUSAND MILES passage above referred to, the cost of freight per ton of goods at TEN MILES per hour, will require to be nearly the double of the rate at EIGHT MILES per hour.

"The cost per ton at TWELVE MILES per hour will require to be three times the rate at EIGHT MILES.

"The cost per ton at FOURTEEN MILES per hour will require to be five times the rate at EIGHT MILES.

"The cost per ton at SIXTEEN MILES per hour will require to be nine times the rate at EIGHT MILES.

"The cost per ton at EIGHTEEN MILES per hour will require to be twenty-three times the rate at EIGHT MILES.

"And at TWENTY MILES per hour there will be no displacement available for mercantile cargo.

"By applying the same process of calculation to a ship of 5,000 tons' mean displacement, making a passage of THREE THOUSAND MILES, we shall find that, at TEN MILES an hour, the cost of freight per ton will require to be double the rate of freight at EIGHT MILES.

"The cost per ton at TWELVE MILES will require to be three times the rate at EIGHT MILES.

"The cost per ton at FOURTEEN MILES will require to be six times the rate at EIGHT MILES.

"The cost per ton at SIXTEEN MILES will require to be twenty times the rate at EIGHT MILES.

"And at EIGHTEEN MILES per hour there will be no displacement available for mercantile cargo.

"Finally, by applying the same process of calculation to a ship of 5,000 tons' mean displacement on a passage of 6,000 miles, it will be found that the cost of freight per ton at TEN MILES per hour will require to be double the rate at EIGHT MILES.

"The cost per ton at TWELVE MILES per hour will require to be about five times the rate at EIGHT MILES.

"The cost per ton at FOURTEEN MILES per hour will be about sixteen times the rate at EIGHT MILES.

"And at SIXTEEN MILES per hour there will be no displacement available for mercantile cargo.

"Hence, it appears, that for voyages of 1,000 miles and upwards, without re-coaling, the speed of ten nautical miles per hour would involve about double the cost per ton of eight miles, and may, therefore, be regarded as the extreme limit that can be generally entertained for the mercantile purpose of goods' conveyance; and that the attainment on long passages of a higher rate of speed than ten miles (though admissibly practicable) would involve obligations altogether of an exceptional character, such as the special service of dispatches, mails, passengers, specie, and the most valuable description of goods can only meet."



SECTION V.

OCEAN MAIL STEAMERS CAN NOT LIVE ON THEIR OWN RECEIPTS.

INCREASE OF BRITISH MAIL SERVICE: LAST NEW LINE AT $925,000 PER YEAR: THE SYSTEM NOT BECOMING SELF-SUPPORTING: CONTRACT RENEWALS AT SAME OR HIGHER PRICES: PRICE OF FUEL AND WAGES INCREASED FASTER THAN ENGINE IMPROVEMENTS: LARGE SHIPS RUN PROPORTIONALLY CHEAPER THAN SMALL: AN EXAMPLE, WITH THE FIGURES: THE STEAMER "LEVIATHAN," 27,000 TONS: STEAMERS OF THIS CLASS WILL NOT PAY: SHE CAN NOT TRANSPORT FREIGHT TO AUSTRALIA: REASONS FOR THE SAME: MOTION HER NORMAL CONDITION: MUST NOT BE MADE A DOCK: DELIVERY OF FREIGHTS: MAMMOTH STEAMERS TO BRAZIL: LARGE CLIPPERS LIE IDLE: NOT EVEN THIS LARGE CLASS OF STEAMERS CAN LIVE ON THEIR OWN RECEIPTS: EFFICIENT MAIL STEAMERS CARRY BUT LITTLE EXCEPT PASSENGERS: SOME HEAVY EXTRA EXPENSES IN REGULAR MAIL LINES: PACIFIC MAIL COMPANY'S LARGE EXTRA FLEET, AND ITS EFFECTS: THE IMMENSE ACCOUNT OF ITEMS AND EXTRAS: A PARTIAL LIST: THE HAVRE AND COLLINS DOCKS: GREAT EXPENSE OF FEEDING PASSENGERS: VIEWS OF MURRAY AND ATHERTON ON THE COST OF RUNNING STEAMERS, AND THE NECESSITY OF THE PRESENT MAIL SERVICE.

From the foregoing Section it is evident that the cost of running ocean steamers is enormous, and that in the chief element of expenditure it increases as the cube of the velocity. This, although true, is certainly a startling ratio of increase, and calculated to arouse attention to the difficulties of postal marine navigation. Seeing that ocean speed is attainable at so high a cost, we naturally conclude that fast mail steamers can not live on their own receipts upon the ocean.

Since Great Britain established her first ocean steam mail in 1833, she has gone on rapidly increasing the same facilities, until her noble lines of communication now extend to every land and compass every sea. The last great contract which she conceded was last year, to the "European and Australian Company," for carrying the mails on a second line from Southampton via Suez to Sydney, in Australia, at L185,000, or $925,000 per year. And although her expenditures for this service have gradually gone up to above five millions of dollars per annum, she continues the service as a necessity to her commerce, and a branch of facilities and accommodations with which the people of the Kingdom will not dispense. The British Government set out with the determination to have the advantages of the system, whether it would pay or not. They believed that the system would eventually become self-supporting, by reason of the many important improvements then proposed in the steam-engine, and they have ever since professed to believe the same thing. But their experience points quite the other way; and while the service is daily becoming more important to them in every sense, it is also becoming year by year more expensive.

Contracts which the Admiralty made with several large and prominent companies in 1838 they renewed at the same or increased subsidies, after twelve years' operations, in 1850, for another term of twelve years. And so far from those companies with their many ships on hand being able to undertake the service for less, they demanded more in almost every case, and received it from the government. The improvements which they anticipated in the marine engine were more than counterbalanced by the rise in the price of fuel and wages all over the kingdom and the world. In fact, those improvements have been very few and very small. It still takes nearly as much coal to evaporate a pound of water as it then did; and the improvements which have been made were generally patents, and costly in the prime cost of construction to a degree almost preclusive of increased benefits to the general service. At any rate, the latest steam adaptations and improvements have proven unequal to the end proposed, and the cost of the ocean service is now far heavier than it ever has been before, simply because of the greater speed required by the public for the mails and passage.

It had long been hoped that this difficulty of increasing cost in running ocean steamers might finally be overcome by another means; and the whole available engineering and ship-building talent of Great Britain and the United States has been directed not entirely to the engine department, but to the hulls and to the production of a large class of ships, which are admissibly cheaper in proportion to size and expense of running when compared with smaller vessels, if they are always employed and have full freights and passage. It is well established that large steamers run proportionally cheaper than small ones. (See Table III., page 76.) This arises from the important fact that the length increases far more rapidly than the breadth and depth. Consequently the tonnage of the vessel increases much faster than the resistance. In passing through the water the vessel cuts out a canal as large as the largest part of its body, which is at the middle of the ship. If the vessel be here cut in two, the width and depth, or the beam and hold being multiplied together will give the square contents of the midship section. Now, when a vessel is doubled in all of its dimensions, this midship section and consequently the size of the canal which it cuts in the water, does not increase as rapidly as the solid contents of the whole ship, and consequently, as the tonnage. Hence, the resistance to the vessel in passing through the water does not increase so rapidly as the tonnage which the vessel will carry.

To make this clearer, let us suppose a vessel of good proportion, whose length is seven times the beam, or 280 ft. long, 40 ft. wide, and 30 feet deep. The midship section will be 40 x 30 = 1,200 square feet: the solid contents will be 40 x 30 x 280 = 336,000 solid feet. Again, let us double these dimensions, and the ship will be 80 ft. wide, 60 ft. deep, and 560 feet long. The midship section will be 80 x 60 = 4,800 square feet: the solid contents will be 80 x 60 x 560 = 2,688,000 solid feet. Now, comparing the midship sections, and also the said contents in each case we have,

Midship Section, 4,800 ——- = 4 to 1. Increase as the squares: Midship Section, 1,200

Solid Contents, 2,688,000 ————- = 8 to 1. Increase as the cubes. Solid Contents, 336,000

Thus, the midship resistance has increased as four to one, or as the square, while the solid contents, representing the tonnage, have increased as eight to one, or as the cube. It is evident that the ship has but four times the mid-section resistance, while she has eight times the carrying capacity. Therefore the engine power, and the coal and weight necessary to propel a ship of twice the lineal dimensions, or eight times the capacity, would have to be only four times that of the smaller vessel, speaking in general terms; and as a consequence, the price of freight, considering the vessels to run at equal speed, would be but half as much in the larger as in the smaller vessel.

The attempt has been made to seize the evident advantages thus offered by increasing the size of the hull, until our clippers now reach an enormous size, and our steamers are stopping but little short of 30,000 tons. The splendid steamer "Leviathan" was built on this idea, and must prove a splendid triumph in comparative cheapness if she can only get business so as to run full, and keep herself constantly employed in her legitimate business, running. But it is hardly possible that she should be always filled with either freight or passengers. Some of our large clipper ships have experienced this difficulty. The time necessary to load and unload is too great for short routes, although they are well calculated for long passages. If one of these large steamers fail to get plenty of business the losses become exceedingly severe. The prime cost is immense; the interest on the capital and the insurance are very large; and the current expenses are even beyond those necessary for the government of some cities. These hazards all taken together more than neutralize the benefits which arise from extra size and extra proportional cheapness; so that notwithstanding all of the hopes which some have entertained for the cheapening of transport in this way, they are probably doomed to disappointment in the end; and ocean steaming continues as expensive as ever, and is growing even more expensive than it has ever been known since its first introduction. (See Coal Tables, pp. 71 and 75.)

It is clear that, notwithstanding all of the advantages to be gained from increased size, steamers can not support themselves upon the ocean. Let us examine further the case of such a ship as the "Leviathan." I can not see that there is any normal trade in which she can run successfully. She may transport 6,000 tons of measurement goods to Australia; but it will be at the expense of fourteen to sixteen thousand tons of coals if the passage is made in fair time. If not, sailing vessels will subserve all purposes except travel quite as well. And certainly there is no class of freight for Australia or any other portion of the world, which will pay such an enormous coal-bill, and so many other expenses, and the interest and insurance on three and a half to four millions of dollars, just to save a few days in so long a voyage. And if the steamer is to do a freighting as well as passenger business, then a long voyage is essential to her.

Running is the legitimate business of a steamer. Her costly engines are put in her for locomotion. Her large corps of engineers, firemen, and coal-passers, are employed for running her, and are of no use when she is lying still, although necessarily on full pay. Her condition is abnormal and unnatural every day that she is lying at the docks, and taking or discharging freight; and hence, every day that she is thus employed she is not performing her proper functions. A sailing ship can better afford to lie still for weeks and await a freight, or slowly receive or discharge cargo; as she must pay only the interest on her investment, her dockage, the captain, and watchmen, and perhaps her depreciation. The prime investment is much less. She has no costly engines and boilers. So are her current expenses. She has none of the costly employees that I have named, and who can never leave a steamer for a day. But eternal motion, flush freights, flush business, good prices, and constant employment, are everywhere essential to the steamer.

Suppose the "Leviathan" steamer running between Liverpool and New-York. She would be occupied ten days at least in receiving her freight, ten days in running and making port or docks, and ten days in discharging. Then, she would be employed only one third of her time in the business for which she was constructed, running; while during two thirds of it she would be acting simply as a pier or dock, over which freight would be handled. Now, with her costly engines, and costly and necessarily idle employees, she can not afford to be a dock; neither can she afford to lie still so long. Nor can she on such conditions get the freight necessary to her support. The community on neither side of the water would wish fifteen thousand tons of any class of freights which she could transport dumped down upon the docks at one time. They wish it to arrive a little and a little every day, as it is wanted, just enough to supply the market; and will not lie out of the money which they pay for it, and have it nearly a month in market before they need it, just to have it come on the "Leviathan." It must come along in small lots, just as they need it, and it must be shipped the day that it is bought, and delivered as soon as the ship is in, without being the last lot of fifteen thousand tons, and without keeping the owners so long out of their money. Suppose that A. puts the first lot of freight in at London: he will be the last to receive, it in New-York. A smaller steamer taking another lot two days after, will deliver it before the large ship gets half way over. Or, again, the small steamer may leave London with it when the large steamer has nearly arrived at New-York, and deliver the lot here to the owner in advance. Beside not wishing so large a lot at once, they do not wish it all in one place. The double advantage of a great number of small vessels is, that they bring cargo along as it is wanted, and at the same time distribute it at all of the hundreds of large and small ports, without first delivering it at some great mammoth terminus, and then reshipping and distributing it to its final destination.

A gentleman, who is a prominent statesman, recently seriously advised me not to think of establishing a line of mail steamers between the United States and Brazil, for the accommodation of the hundreds of sailing vessels engaged in that trade, but to get up a mammoth company and run five or six thirty thousand ton steamers, like the Leviathan, between Norfolk and Rio de Janeiro. He said that the increased size of the steamer would enable me to carry freight cheaper than sailing vessels. The reasoning was neither very clear nor convincing to me on behalf of the mysterious capacities which he attributed to large steamers. I suggested that, in the first place, there was no cargo passing either way between the United States and Brazil which could afford to pay steam transportation under any circumstances; that so large a cargo could never be obtained at once in Rio de Janeiro or elsewhere; that the merchants of this country did not wish it all landed at one place; that it would cost as much to remove it from Norfolk to the place of consumption, as it would from Rio de Janeiro to its final destination; that they did not wish it delivered all at once, but in small lots at a time, and distributed where it was needed; and that, even if it were at all practicable, which no business man could for a moment believe, the people would not be willing to have a fruitful field of industry in shipping occupied by some great overgrown company, with a great coffee monopoly, which would surely follow. Too much has been expected of large ships. The clipper "Great Republic" is not freighted half of her time. The "Leviathan" can not pay in freighting unless she runs to Australia and the East-Indies, and runs slowly, on very little coal. She may do very well with a voluntary cargo, which will load and unload itself in a hurry, such as a cargo of emigrants, and not steaming at too a high a speed. But it would require a dozen steamers as tenders to bring these emigrants from Ireland, Bremen, Havre, Hamburgh, Amsterdam, and other European cities, to her central depot in England. She would, however, become a most useful if not indispensable transport vessel for the British Government.

If the large class of steamers can not live on their own receipts, much less can the small. An adequate speed for the mails leaves no available space for cargo. The ship may carry two or three hundred tons of freight; but it pays perhaps but little more than the handling and the extra coal necessary to transport its extra weight. As a general thing, it may be safely said that when a vessel is well adapted to the mails and passengers she is filled with her own power, that is, with heavy engines, large boilers, and a large quantity of fuel, as also with her provisions and baggage. We have already seen how the size and weight of engines and boilers must increase, as well as the bulk and cost of the fuel, to gain a little speed. But it is not generally known how large a quantity of consumable stores and baggage go in a well-supported mail packet. The greater the postal efficiency of a steamer the less is it able to carry freight; and the time will doubtless soon come when the fast mail packets will take nothing except a few express packages. The Persia now takes scarcely any freight, and the Vanderbilt can not think of doing it when she makes fast trips. It is very probable that the whole system of the ocean will be materially changed; and that while clippers and slow propellers carry the fine freights, fast vessels filled with their own power will carry the mails and passengers. And in doing this, they can not, of course, support themselves; neither will they conflict with private enterprise in freight transport. It is now the case to a large extent on most of our American lines.

While the ocean mail steamer must be fast and costly, for the better acceleration of correspondence and the accommodation of passengers, she must also go at the appointed hour, whether she is repaired or not, and wholly irrespective of her freight and passenger list. There must be no delays for a lot of freight, or for a company of fifty passengers who have been delayed by the train. She has the mails, and must go at the hour appointed, whatever it may cost the company, and however large a lot of costly stores may have to be thrown away. This punctuality, while it is the means of securing small lots of freight, prevents also the accommodation of the ship's day of sailing to arrangements which might otherwise be profitable. This punctuality in sailing always necessitates large extra expense in repairs. It frequently happens that companies of men work through the nights and on Sundays; getting much increased prices for such untimely labor, and being far less efficient in the night than in the day. If the steamer has had a long passage from whatever causes, she discharges whatever she has and takes in her coal in a hurried and costly way, frequently at fifty per cent. advance on the cost necessary for it if she had ample time. The only means of avoiding these exigencies is by having spare ships, which cost as much as any others, but which add nothing whatsoever to the company's income. It may be safe to say that in every mail company it is necessary to have one spare, and consequently unproductive, ship for every three engaged in active service. This thirty-three per cent. additional outlay would not be necessary except on a mail line, where punctuality was positively demanded. Yet, it is one of the heavy items of expense to be incurred by every company carrying the mails, and with which they can not in any wise dispense, however well their ships may be built. The "Pacific Mail Steamship Company" in running their semi-monthly line from Panama to California and Oregon, keep constantly at their docks eight unemployed steamers and one tow-boat, ready for all exigencies and accidents, and could keep their mails going if nearly their whole moving fleet should be sunk at once. No wonder that they have never missed a single trip, or lost a single passenger by marine accident since they first started in 1850. But there is another class of costs in running ocean steamers, which amount to large sums in the aggregate, and of which the people are generally wholly ignorant. I allude to the items, and what may be called "odds and ends." It is easily imaginable that a company has to pay only the bills for wages, for fuel, and for provisions, and that then the cash-drawer may be locked for the voyage. Indeed, it is difficult for those accustomed to the marine steam service to sit down and enumerate by memory in one day the thousand little treasury leaks, the many wastages, the formidable bill of extras, and the items which are necessary to keep every thing in its place, and to pay every body for what he does. The oil-bill of a large steamer would be astonishing to a novice, until he saw the urns and oil-cans which cling to every journal, and jet a constant lubricating stream. The tools employed about a steamer are legion in number, and cost cash. We hear a couple of cannon fired two or three times as we enter and leave port, or pass a steamer upon the ocean, and consider it all very fine and inspiring; but we do not reflect that the guns cost money, and that pound after pound of powder is not given to the company by the Government or the public. The steamer carries many fine flags and signals, which cost cash. An anchor with the chain is lost; another costs cash. Heavy weather may be on, and it takes some hours to get into the dock. The extra coal and the tow-boat cost cash. The wheel-house is torn to pieces against the corner of the pier, and the bulwarks are carried away by heavy seas; but no one will repair the damage for any thing short of cash. A large number of lights are by law required to be kept burning on the wheel-houses and in the rigging all night; but no one reflects that it took money first to purchase them, and a constant outlay to keep them trimmed and burning. People suppose that the captain, or steward, or some body else can take a match and set the lamp off, and have it burn very nicely; but there are only a few who know that it takes one man all of his time to clean, fill, adjust, light, and keep these lamps going, as well as have them extinguished at the proper time.

I saw to-day a case in point as regards accidental expenses. The splendid steamship Adriatic sailed at 12. The wind was very high from the south, and almost blowing a gale. She was lying on the southern side of the dock, while the Atlantic was lying with her stern at the end of the dock, near where the Adriatic had to pass in going out. At the moment of starting, three strong tow-boats were attached to her bow, and endeavored as she went out to draw her head against the wind, down stream. But they proved insufficient to the task. The vessel crushed down the corner of the dock, ran into the Atlantic, and carried away her stern bulwarks, crushed one of her own large and costly iron life-boats, and damaged one of her wheel-houses. Now, who of the two hundred thousand spectators that lined the docks, would pay the two thousand dollars for the life-boat, a thousand for repairing the dock and vessels, and the bill for the three tug-boats for two hours each?

Moreover, we see a pilot get on the steamer at New-York, another at Southampton, and a third at Havre; but we seldom reflect that the steamer has to pay a large price to each one of them, both going and coming. Take the coasting steamers, running between New-York and Savannah, or Charleston. It appears singular that the New-York pilot goes all the way to Savannah, that the Savannah pilot comes all the way to New-York, and that the steamer pays for both of these men all the time, and feeds them on board all of the time. Yet it is so. Such is the law; and it amounts to a good many thousands during the year. And all this, the company must pay, as a part of those items which take cash, but for which the company never gets any credit from the public or the Government. Whenever a little accident occurs to the steamer, it must be towed a few miles at a high price by a tug-boat. Whenever the Government or friends and visitors come on board, they expect to be liberally entertained; yet the company must pay for it, or be considered mean and unworthy of the Government's patronage. Each ship must have an experienced surgeon, whose wages must be paid like those of other persons employed, and an apothecary's room and outfit. The ship must be painted and varnished, and overhauled at every trip; the upholstering and furnishing must be often renewed; stolen articles must be replaced; and the breakages of table-wares constantly renewed. All of this costs cash.