Ships and Shipping. 153 



centage they bear to the gross tonnage of the ship ; the 

 excess above one-half per cent is added to the tonnage 

 of the ship. It is provided, however, that in respe6l to all 

 other ships the dedu6lions shall, if the Board of Trade 

 and the owner both agree thereto, be estimated in the 

 same manner, but either they or he may, in their discre- 

 tion, require the space to be measured, and the dedu6lion 

 estimated accordingly ; but in this case the tonnage 

 is to consist of the space a6lually occupied for the proper 

 working of the boiler and machinery, with the addition in 

 ships propelled by paddle wheels of one-half, and in 

 ships propelled by screws of three-fourths of the tonnage 

 of said space. 



In the allowances for engine room in steamers, space 

 or spaces above crown of engine room and above the 

 upper deck, framed in, for the machinery and for 

 the admission of light and air, shall not be included in 

 propelling power space, except the owner should so request 

 the Board of Trade, in writing, and shall not be included 

 in pursuance of such request, unless that portion is first 

 included in measurement of gross tonnage, and that a 

 Surveyor appointed under the fourth part of the Mer- 

 chant Shipping A61, 1894, certify that it is duly con- 

 stru6led safe and seaworthy, and cannot be used for any 

 other purpose. 



By the Merchant Shipping A61, 1854, it was enafted 

 that in the admeasurement of ships, the depth shall be 

 taken to the upper side of the floor-timber at the inside 

 of the timber strake. At that time most of the ships in 

 the mercantile marine were built of wood ; they have 

 subsequently, for the most part, been built of steel or iron, 

 and have neither floor timber or timber strakes, but are 



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