rine 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" i