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 × 30 = 1,200 square feet: the solid contents will be 40 × 30 × 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 × 60 = 4,800 square feet: the solid contents will be 80 × 60 × 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 employées 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 employées, 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 dépôt 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.