120, actual 234; Firefly, nominal 52, actual 86.6; Ferret, nominal
52, actual 88; Monarch, nominal 200, actual 378. In the case of swift
vessels of modern construction, such as the Red Rover, Herne, Queen, and
Prince of Wales, the coefficient appears to be about 2550; but in these
vessels there is a still greater excess of the actual over the nominal
power than in the case of the vessels previously enumerated, and the
increase in the coefficient is consequent upon the increased pressure of
the steam in the boiler, as well as the superior form of the ship. The
nominal power of the Red Rover, Herne, and City of Canterbury is, in each
case, 120 horses, but the actual power of the Red Rover is 294, of the
Herne 354, and of the City of Canterbury 306, and in some vessels the
excess is still greater; so that with such variations it becomes necessary
to adopt a coefficient derived from the introduction of the actual instead
of the nominal power.

547. _Q._--What will be the average difference between the nominal and
actual powers in the several classes of vessels you have mentioned and the
respective coefficients when corrected for the actual power?

_A._--In the first class of vessels experimented upon, the actual power
was about 1.6 times greater
than the nominal power; in the second class, 1.67 times greater; in the
third class, 1.7 times
greater; and in the fourth, 1.96 times greater; while in such vessels as
the Red Rover and City of
Canterbury, it is 2.65 times greater; so that if we adopt the actual
instead of the nominal power in
fixing the coefficients, we shall have 554 as the first coefficient, 694
as the second, 832 for the
third, and 806 for the fourth, instead of 925, 1160, 1430, and 1580 as
previously specified; while
for such vessels as the Red Rover, Herne, Queen, and Prince of Wales, we
shall have 962 instead of
2550. These smaller coefficients, then, express the relative merits of
the different vessels without
reference to any difference of efficacy in the engines, and it appears
preferable, with such a
variable excess of the actual over the nominal power, to employ them
instead of those first referred
to. From the circumstance of the third of the new coefficients being
greater than the fourth, it
appears that the superior result in the fourth set of experiments arose
altogether from a greater
excess of the actual over the nominal power.

548. _Q._--These experiments, you have already stated, were a