246 Method of obviating 



stood, that the idea of applying this invention to the fid of 

 a top-gallant mast originated with captain Wells, who 

 well understood the principle, and had received from him a 

 model of the invention. 



When it is required to strike a top-gallant mast, the top 

 ropes are hove tight, and the pin which keeps the horizontal 

 wedges in their place is taken out, by one man going aloft 

 for that purpose; ihe other horizontal wedge is worked in 

 the fid, as shown in the drawing and model that accompany 

 this statea)ent. 'I'he upper part of the fid hole is cut to 

 form the vertical wedge. The advantage derived from fid- 

 ding top-gallant masts in this way is, that they can be 

 struck at the shortest notice, and without slacking the rig- 

 ging, which is frequently the cause of springing and carry- 

 ing them away, particulariy those with long pole heads. 

 The angle of the horizontal wedges for the fids of masts 

 should be about twenty degrees. 



The above account was accompanied with certificates 

 from sir John Henslow, surveyor of the navy ; Mr. M, 

 Didram, master-shipwright of Portsmouth-yard; and Mr. 

 John Carpenter, foreman of Sheerness dock-yard, conT- 

 firming Mr. Seppings's statement. 



Reference to the Engraving of Mr. Seppings's method oj" 

 obviating the necessity of Ijj'ting ships. Plate IV. 



This plan and section of a seventy-four gun ship de-r 

 scribes the method of obviating the necessity of lifting ships, 

 when there may he occasion to put additional false keels to 

 them, or to make good the imperfections of those already 

 on; also, when it may be necessary, to caulk the garboard 

 seams, scarples, the keel, &c. ; by which means a very con- 

 siderable part of the expense will be saved, and much time 

 gained. The blocks are cleared, and again returned by the 

 following process. A sufficient number of shores are placed 

 xmder the ship to sustain her weight, and set taught, sta- 

 tioned as near the keel as the working of the battering- 

 rams fore and aft will admit. Avoid placing any opposite 

 the blocks, as they would in that case hinder the return of 

 the wedges with the battering-rams. A blow must theri 

 be given forward on the outer end of the iron wedges with 

 the battering-rams in a fore and aft direction, which will 

 cause them to slide aft, as shown in the plan. The batter>» 

 ing rams abaft then return the blow, and the wedges again 

 come forward ; by the repetition of this operation, the 

 wedges will be with great ease cleared, and the angular 



block 



