92° REPORT—1857. 
out of their berths, protect themselves beforehand ; and what remedy had 
they after the fact, or what compensation ? 
If the displacement principle were adopted, tables might be constructed 
for all known forms of vessels, which would give the displacement at any 
draught of water, and upon the difference of light and load draught the 
duties should be payable: this would set at rest the question between sailing 
vessels and steamers. 
Secondly.—As to aunitof HP. Here the commercial part of the question 
resolves itself into a matter of bargain, and neither buyer nor seller can be 
benefited by interference. The buyer has but to specify the work he requires, 
and to make his contract accordingly. But the scientific part of the ques- 
tion assumes another aspect. 
Improvement can make but slow and fitful progress when the power exerted 
and the power given out are known only to a few of the initiated. What 
science wants to know in each ease is, the indicator power and its results, in- 
cluding the consumption of fuel. Any measure of power which does not em- 
brace the weight of fuel, which is the originator of the power, must be 
incomplete. 
Any general expression must include the boiler as well as the cylinder, 
and it would mean a given weight moved through a certain space in a cer- 
tain time, with a certain weight of fuel. We have not as yet data for such 
an expression. 
The accompanying pamphlet, which I have had printed for private circu- 
lation, may perhaps throw some light upon this subject, and I have marked 
the passages bearing on the immediate question of power. 
I have now before me a table printed by the Admiralty last year, and 
showing “results of trials made in her Majesty’s screw ships and vessels.” 
These results are useful as far as they go, but they do not go far enough, 
and the particulars of the table might be simplified and amended. They 
involve a theory, whereas facts alone are wanted. ‘The trials were made in 
smooth water only, and do not contain any account of the consumption of 
fuel. 
The passages marked in the pamphlet and the tables A and B will show 
how necessary it is to have the performances of vessels and engines at sea, 
in order to institute any comparisons towards the deduction of laws, and 
that the consumption of fuel is indispensable. 
March 24, 1857. C. R. Moorsom, Rear Admiral. 
No. 8.—Mr. James Yates (Member of the Committee)- 
To the Shipping Registration Committee of the British Association. 
I am very desirous of directing the attention of the Shipping Registration _ 
Committee to the following considerations :— 
The party, if it may be called a party, which we considered as opposed to 
ourselves, and which we may probably regard as represented by Mr. G. 
Moorsom, do not appear to be in such entire opposition as may at first be 
imagined, and certainly, we are not entirely opposed to them. On the con- 
trary, we appear to agree in the most important and fundamental points. 
1. We agree in regard to the necessity of internal measurement as an 
element of tonnage registration, being the space inside a vessel, or under 
cover, which may be used to carry either cargo or passengers. 
2. We agree in regard to Sterling’s rule as a recognized method of ad- 
measurement, available for calculating the entire contents of a ship of any © 
form, measured either internally or externally. 
SS 
i lly Pata : 
