The coefficient,
which is contained in the thirteenth column of the table, viz.:
Dis 2/3 x speed cubed
-------------------------
I.H.P. x sqrt(entrance.)
---------------
10
generally comes out for ships of similar type more nearly a constant
in the true sense of the word than the corresponding Admiralty
constant. As an example, we have the curves of resistance and horse
power for the City of Rome and the Normandie, a large vessel of 6,000
tons, which the Barrow Company built for the Compagnie Generale
Transatlantique, in which the coefficient of fineness and the form of
the lines pretty closely resemble each other below water; and if we
take from the curves the corresponding speeds and horse powers, and
work out the constants by the two systems, we have at 14 knots the
Admiralty constant for the City of Rome 322.2, and for the Normandie
304.8; and taking for a modified form of constant, the City of Rome
gives 253.7 and the Normandie 251.9, which, as will be seen, are much
closer together. Similarly, at 15 knots the Admiralty constant for the
City of Rome is 310, and for the Normandie 295.2, while a modified
constant comes out for the former at 245, and for the latter 244,
again agreeing almost identically. The same at 16 knots, for the City
of Rome the Admiralty constant comes out 297.
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