ON THE MEASUREMENT OF SHIPS FOR TONNAGE. rh! 
define the measure of power available for the propulsion of the ship (the 
capability of engines for the production of working power with reference to 
their nominal horse-power being notoriously, in some cases, the double of 
what it is in others), what steps should be taken to remedy this incongruity ; 
and, presuming on its being determined to adopt some specific measure of 
power as the legalized standard unit of power, what definition, measure, or 
amount of power, should (in the opinion of the respective members of this 
Committee) be adopted as the statute unit of marine engine-power, and by 
what name should it be called, viz. whether “ horse-power,” or “marine horse- 
power,” or “statute-power,” or “units of power,” or other denomination? 
8. The respective members of Committee are requested to state their 
opinion whether it be advisable that any particular mode of prosecuting the 
details of measurement and working out the calculations thereof (such, for 
example, as Sterling’s rule) should be prescribed by law for the measurement 
of ships, as is done by the Merchant Shipping Act of “1854;” or, ought 
the system of taking the measurements and working out the calculations to 
be left to the discretion of the chief officer of the department on whom the 
responsibility for the scientific prosecution and accuracy of the calculations 
will professionally rest, as in the case of the astronomical calculations for the 
Nautical Almanac published by Government, but for which the system of 
prosecuting the observations and deducing the calculations is not prescribed 
by law, but determined and improved from time to time, as may be, by the 
astronomer; and if it be considered that a prescribed mode of working out 
the calculations ought to be fixed and enforced by law, is the rule (Sterling’s) 
_ now enforced by the Merchant Shipping Act the best rule now known and 
practised for calculating the cubature of ships? 
It is not expected that the respective members of this Committee will indi- 
vidually express opinions on each and all of the various points above sub- 
mitted for their consideration, but it is requested that each member, according 
to his special avocation, experience, or acquirements, will address himself to 
those points on which he may be regarded as an authority ; and as the com- 
plete elucidation of the matters referred to this Committee, with a view to the 
public good, is the duty assigned to this Committee, it is requested that each 
member will not only express his own opinion, but seek information and confer 
with others within his sphere conversant with the matters referred to, though 
not members of this Committee ; and for the purpose of aiding in this object 
of obtaining information, duplicate copies of the poinis of investigation above 
propounded are enclosed herewith. 
It is further purposed, that as soon as the written opinions or answers of the 
‘respective members of the Committee, to be given in on or before Monday, 
the first day of December, shall be received by the Secretary, addressed as 
above directed, copies thereof will be forwarded to each of the members of 
this Committee for mutual information, and in order that further confirma- 
tion, or correction, or amendment of the original opinions, may be thus 
elicited, to constitute the base of the general report to be discussed and 
settled at a future meeting of this Committee, preparatory to being presented 
‘to the British Association at their ensuing meeting. 
I am, Sir, your obedient Servant, 
CHARLES ATHERTON, 
Woolwich Dockyard, Nov. 6, 1856. Secretary, pro tem. 
No. 2.—Mr. J. Scorr Russevzt (Member of the Committee). 
. Ast, 2nd, 3rd. The original object of legislation for tonnage appears to 
