GHT 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 firs