90 REPORT—1857. 
which is loaded so as to sink below a certain draught of water ; and that her 
registered tonnage should comprise the weight of water between her assigned 
Joad draught and that draught which she would have when fit for sea, with 
crew and stores and everything on board, except that by which she earns 
her freight. Supposing such a principle to be admitted, the method of de- 
termining such tonnage would not be difficult. 
I annex an example. But the question at this moment is, how is this 
principle of registration to be tested, and, if sound, carried out ? 
The agitation of it, so that the public may some day see they have an 
interest in it, must do good, and I shall, therefore, be glad to subscribe towards 
the expenses of your association. 
Next, as to the unit of HP. When a person wishes to buy an engine, he 
need not trouble himself about the nominal HP, but specifying the nature 
and extent of the work it is to do, he can bind the engine builder to results. 
The contractor, on his part, has his own rules for making the instrument. 
It then becomes a question of specific performance between the parties, with 
which the public is not concerned. But with the question of the improve- 
ment of engines and the improvement of vessels, the public has every con- 
cern, and improvement can make but slow and fitful progress when the power 
exerted and the power given out in any case are not known, or known only 
to a few persons, and that by special experiment only, and not by stated 
performance. 
In the pamphlet I have had printed for private circulation, of which you 
have a copy, I have expressed my opinion on this question of the improve- 
ments of engines and vessels, and your Committee may probably coincide 
in my VIews. 
I think then, that it is of little consequence to what unit we refer the ex- 
pression HP, if in any given case we can know the power exerted ; and it is 
the indicator power and its results, including the consumption of fuel, that is 
wanted. 
Any measure of power must be incomplete without the weight of the fuel 
which is the originator of the power, and in any general expression we must 
include the boiler as well as the cylinder. 
Such expression would consequently mean a given weight moved through 
a certain space in a certain time with a certain weight of coal. 
Now, as yet we have no data for such an expression. I must apologise 
for so hasty and incomplete a statement, but I would not let the day pass 
without an acknowledgment of your note. Having returned home only on 
Saturday, and leaving home again tomorrow, I have not at present time to 
proceed further with the subjects of the printed letter. 
I am, Sir, yours truly, 
J. Yates, Esq. C. R. Moorsom. 
(EncLosurE. ) 
Let the dimensions of a vessel at her light draught ready for sea, except 
cargo, be— 
Teength v0: ivedia os eee od dea. 40 s300.feek 
Brbadthiier iis. 2G Be iiatis« ot) SO 
DD vista Blt c.ioi cas. tare wenn aioli as! 15 
Assume the coefficient of displacement, = 45. 
Then, UXxBxD X, 45—=2892°825 tons. 
35 
