436 REPORT — 1856. 



ships built previously to the month of May 1855, when this Act came into 

 operation, the adoption of this law is not compulsory. Merchants have the 

 privilege of retaining the former registration of some ships, and getting such 

 others of their ships measured and registered under the new Act as they may 

 think fit to select for re-registry, so that the term " tonnage " may now signify 

 " builders' tonnage," old measure, under the Act of 1773, or tonnage under 

 the Act of 1833, or tonnage under the Act of 1854; and these are three 

 totally different systems of admeasurement, having no definite ratio to each 

 other. Moreover, the unit of tonnage under the Act of 1854) being based 

 on internal roomage measurbig up to the deck, affords no certain indication 

 of the displacement of a ship when loaded fit for sea, nor does it afford any 

 assurance whatever as to the tons' weight of cargo that a ship will carry ; for 

 example, by adopting the cellular principle of build now introduced in the 

 construction of iron ships, a ship of 10,000 cubic feet of internal roomage, or 

 100 tons register tonnage, may have such external displacement as would 

 safely float with the whole internal roomage filled with iron, and therefore 

 weighing no less than 1000 tons of dead weight, or ten times the register 

 tonnage, and the registration of steam-ships is open to similar delusion as to 

 their capability for weight of cargo. So much for the mercantile liberties 

 that may possibly be introduced and taken with our statistics of exports and 

 imports so far as they may be based on the tonnage registration of shipping 

 under the Act of 1854. 



The abortiveness for statistical and scientific purposes which has hitherto 

 attended all legislation on tonnage registration, appears to have been occa- 

 sioned by the attempt to embrace under the one term "tonnage," two things 

 which have no fixed ratio to each other, namely, tonnage by bulk, and ton- 

 nage by weight. The law has not comprehended the double mercantile use 

 and application of the term " ton " by providing for the separate and distinct 

 registration of each, namely, tonnage by bulk and tonnage by weight, the 

 capability of ships for holding bulk tonnage being dependent on internal room- 

 age ; but the capability of ships for carrying weight tonnage being dependent 

 on external displacement, a distinction which is not noticed by the new law 

 of tonnage admeasurement under the Act of 1854. 



2nd. As to marine engine-power. Although Watt originally defined the 

 unit of power, which he denominated horse-power, as equivalent to 33,000 lbs. 

 weight raised one foot high in one minute of time, and invented a mecha- 

 nical device or instrument called a "steam-indicator," whereby the variable 

 pressure of the steam in the cylinder and consequently the working power 

 of steam-engines could be readily ascertained (whence the working power so 

 ascertained was denominated the " indicated horse-power"), all which ar- 

 rangements of Watt put the working operation of the steam-engine originally 

 on a scientific base, defined by a standard unit of power admeasurement, 

 still this definite unit of power was never recognized by law, and conse- 

 quently the steam-engine was no sooner applied to maritime purposes, than 

 the rivalry of trade introduced a practice under which the nominal, or contract 

 power of engines, did not specifically regulate the working capability of the 

 engine delivered. Engines were not objected to by the purchaser if their 

 working capabilities were in excess of the nominal power, and engineers 

 themselves voluntarily supplied marine engines working up to an " indicated 

 power far in excess of the nominal " power, for the purpose of thereby dri- 

 ving the new vessel at a higher rate of speed than that attained by some rival 

 vessel with the same nominal power. Reputation for the production of fast 

 steamers depended on beating the rival boat, not on the mode of effectin-^ 

 that object, The shipping interests and their working craftsmen, M\* 



