not so great as
has heretofore been supposed, and that, in fact, the main resistance is
that due to the friction.

[1] This statement supposes that there is no difference of level between
the water at the bow and the water at the stern. In the experiments on the
steamer Pelican, the resistance was found to vary, as the 2.28th power of
the velocity, but the deviation from the recognized law was imputed to a
difference in the level of the water at the bow and stern.

EXPERIMENTS ON THE RESISTANCE OF VESSELS.

542. _Q._--Have experiments been made to determine the resistance which
steam vessels experience in moving through the waters?

_A._--Experiments have been made both to determine the relative resistance
of different classes of vessels, and also the absolute resistance in pounds
or tons. The first experiments made upon this subject were conducted by
Messrs. Boulton and Watt, and they have been numerous, long continued, and
carefully performed. These experiments were made upon paddle vessels.

543. _Q._--Will you recount the chief results of these experiments?

_A._--The purpose of the experiments was to establish a coefficient of
performance, which with any given class of vessel would enable the speed,
which would be obtained with any given power, to be readily predicted. This
coefficient was obtained by multiplying the cube of the velocity of the
vessels experimented upon, in miles per hour, by the sectional area of the
immersed midship section in square feet, and dividing by the numbers of
nominal horses power, and this coefficient will be large in the proportion
of the goodness of the shape of the vessel.

544. _Q._--How many experiments were made altogether?

_A._--There were five different sets of experiments on five different
classes of vessels. The first set of experiments was made in 1828, upon the
vessels Caledonia, Diana, Eclipse, Kingshead, Moordyke, and Eagle-vessels
of a similar form and all with square bilges and flat floors; and the
result was to establish the number 925 as the coefficient of performance of
such vessels. The second set of experiments was made upon the superior
vessels Venus, Swiftsure, Dasher, Arrow, Spitfire, Fury, Albion, Queen,
Dart, Hawk, Margaret, and Hero-all vessels having flat floors and round
bilges, where the coefficient became 1160. The third set of experiments was
made upon the vessels Lightning, Meteor, James Watt, Cinderella, Navy
Meteor, Crocodile, Watersprit