184 



METHOD OF OBVIATING THE 



wedges, were well executed, and rubbed over with foft fomp ; 



for the purpofe of experiment. They were -then placed in;.»«j 



dock, in his Majefty's yard at Plymouth, in which a floop of - 



Andoprefted war was to be docked; on examining them after the veflel 



ijpon them, and ^^as in, and the water gone, they were ail found to have kept:; 



fhoicd up< 



their, fituations, as placed before the fbip refted upon them. 



by battering 

 rams. 



fupported on 

 wheels. 



Shores in their wake were then ereded to fuftain the (liip. 

 The horizontal prior to the faid blocks being taken from under the keel. The 

 wedges were ^^ proccfs of clearing them was, by applying the power of 

 bittering-rams to the fides of the outer ends of the horizontal *. 

 wedges; alternate blows being given fore and aft; by which > 

 means they immediately receded, and the vertical wedges < 

 were difengaged. It was obferved, even in this fmall (hip^ 

 that the block which was formed of horizontal wedges of nine 

 degrees, came away much eafier than thofe of feven, and the 

 one of feven, than that of five. In removing the aforefaid 

 blocks by the power of.lhe battering-rams, which were fuf^ 

 pended in the hands of ithe men employed, by their holding 

 ropes pafled through holes for that purpofe, it was remarked 

 by Mr. Seppings, that the operation was very laborious to ~ 

 the people ; they having to fupport the weight of the batter- 

 ing-rams, as well as to let tiiem in motion. He then con- 

 ceived an idea of affixing wheels near the extremity of that 

 part of the rams, which ftrikes the wedges. This was done 

 before the blocks were again placed ; and it has fince been 

 found fully to anfwer the purpofe intended, particularly in 

 returning the horizontal wedges to their original fituations, 

 when the work is performed for which ihey were difplaced ; 

 the wheels alfo giving a greatincreafe power to the rams, and.; 

 decreafe of labour to the artificers ; befides which, the blows, 

 are given with much more exa^nefs. The fame blocks were 

 again laid in another dock, in which a two-decked fliip of 

 the line was docked. On examination they were found to 

 be very feverely prelTed, but were removed with great eafe. 

 They were again placed in another dock, in which a three- 

 decked fliip of the line was docked. This fliip having in her fofe- 

 mafland bowfprit, the blocks were put quite forward, that being 

 the part which preflTcs them with the greatefl force. As foon as 

 the water was out of the dock, it was obferved, that the ho» 

 o/the veff-'f was ^^^oni'dl wedges of nine and feven degrees had receded fome 

 capable of prelT- feet from their original fituations. This afforded Mr. Seppings 

 ^^%°ts-^ ^ fatisfa^ory proof, which experience has fince demonfirated, 

 ^' «"» - (though 



Other experi- 

 ments. 



It was found 



