547 

 MODERN INVENTIONS. No. III. 



ROBERTS'S NEW FID HARRIS'S LIGHTNING CONDUCTORS WKTTERS- 

 DETT'S PATENT METALLIC SHEATHING WATSON'S LIFE PRESER- 

 VER CANNING'S LIFE RAFT ROGERS'S CAT-HEAD STOPPER AND 

 BATTEN'S PATENT CHAIN CABLE STOPPER. 



AGAIN we are upon the waters. Fancy resumes her sketch, and 

 flings over the dull solidity of matter of fact, the undulating gossamer 

 of fiction. Yielding to her wayward impulse, we will first examine 



ROBERTS'S NEW FID. Nay, start not, gentles there is no occasion 

 for your going aloft to examine it not even upon deck ; for here we 

 have a model at hand. But before we proceed to describe this miniature 

 representation of the manner in which our slender topmast is fidded, we 

 must inform you, that the earliest method of securing the topmast, after 

 being bowsed up to its proper position, was by driving a conically- 

 shaped piece of lignum vitaa, or other strong and durable wood, into an 

 aperture formed in the lower end of the topmast ; so that the ends of 

 the fid, extending on each side of the topmast, might rest on the trus- 

 sell-trees, and, carrying the weight of the topmast, confine it to its 

 natural situation. Occasional improvements were made in the shape 

 and proportions of this fid, but it was always found exceedingly difficult, 

 and sometimes impossible, to be removed in stormy weather, unless the 

 rigging and stays were loosened, and the risk of having the upper masts 

 carried away being thereby considerably increased. 



The active genius of invention has within a few years produced many 

 plans to obviate these disadvantages, among which, the lever fid of Mr. 

 Rotch stands pre-eminent ; but even this has not fully answered the 

 expectations that were formed of it, nor have the various modifications 

 by Admiral Brooking, and other patentees, been more successful than 

 the original. Instead of following the method adopted in all the pre- 

 ceding modes of fidding, by throwing the weight of the topmast upon 

 the trussell-trees, which are in turn supported by the lower mast, Mr. 

 Roberts contrives, by a very simple expedient, to suspend the weight at 

 once upon the latter, which, you will observe, he does in this way. 

 Against the fore part of the lower mast, at a sufficient distance from the 

 head of it, he fixes a stepping piece for the topmast to rest upon ; the 

 head of this stepping piece is cut so as to form an inclined plane, sloping 

 forward, and from the after part of the topmast heel a corresponding 

 section is cut out, so that when the topmast is raised to its intended 

 height, the stepping piece in the lower mast occupies the place of the 

 section that has been cut away from the former. We have shewn that 

 the head of the stepping piece is an inclined plane, and in order to make 

 the topmast slide into its proper position upon that plane, a large wedge 

 is introduced between the fore part of the topmast heel and the fore 

 cross-tree; by driving this wedge the topmast is forced up and 

 securely confined to its place, and may be as easily released, by putting 

 a small block of wood, a handspike, or any thing else that niay be at 

 hand to form a fulcrum, at a little distance from the wedge, and by 

 inserting the end of a crowbar, or other convenient lever, into one of a 



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