J()8 



Proceedings of Learned Siocieiies. 



[Nov. f. 



otlicr as to admit the chain to bed with-' 

 out the dangt:i- of ii double coil ; by thele 

 means the links are retained at right an- 

 gles with each other, the only poiition for 

 free and luiitoiin nioiiou. 



The links of the clmins are made as 

 fliort as poflible, for the purpofe of in- 

 creafing their flexibility, and they are 

 rteJ'ed perfecdy free from twill, in the 

 piiilies, and on the barrels. 



When iifiulied in blocks, the grooi'cs 

 in the pullies prevent the dill'eront falls of 

 the chain from coming in contact, and 

 render plates between them totally un- 

 neceliary ; the pullies are in confequence 

 brought clofcr together, the angle of the 

 fall from block to block conliderably di- 

 Biinilhed, and the friction againll the 

 plates entirely avoided. Brafs guards, 

 with grooves oppofite to thole in the pul- 

 lies, are rivetted to the blocks to prevent 

 the chain getting out of its birth from any 

 accidental circumllance. This method 

 of working chains has been applied to 

 cranes capable of carrying from ten to 

 fifteen tons, and to ftcam-cngines ufed 

 in raifuig coal and ore from niiues; and 

 in all caies we are allured, it lias pcribmi- 

 cd the buhnefs with the utmoll fafcty, 

 uniformity, and tle\ibility. 



The fame method is applicable, at a 

 trifling expence, to all machines at pre- 

 fcnt worked by ropes, or by chains in the 

 uiiml way. It is alio airumed, contrary 

 to the general opinion, that chains are 

 fafer than ropes, for^ it is an efiabliflied 

 axiom that thofe bodies whofe fibres arc 

 moll in the direction of the ftrain, are the 

 leall liable to be pulled afunder. The 

 difcovery is of farther additional import- 

 ance, as it fubllitutes, a durable article 

 for a very pcriiliable one, and gives em- 

 ployment to our own mimufattories at 

 the cxpenfe of foreign importations. 



The truth of JNIr. Gilpin's ftatement is 

 amply confirmed by refpedtable certifi- 

 cates. 



Mr. Thomas Parker has received a 

 premium from this Society, for an in- 

 vention of a Machine for the ufe of Shoe- 

 makers to perform their work in a Hand-, 

 ing pofture, and thereby to prevent all 

 thofe diforders which, it is known, a 

 bending pofture of the body is liable to 

 engender. 



The filver medal and ten guineas were 

 given to Mr. Salmon of Woburn, for his 

 Geometrical Quadrant and Staff, which 

 ferves for plotting ; as a level and calcu- 

 lator for the ufe of navigation and land- 

 furveying; for afcertaining inaccellible 

 diflances, and for demouftrating tvud de- 



termining various problems in geometry 

 and trigonometry. In the flatf there is 

 an improvement, fvi. a, fcrew at the bot- 

 tom, by means of which the flalF may be 

 readily fixed in the ground, in a manner 

 that it could not be without it, nor couldl 

 the infirument be ufed without the fcrew. 



Ten guineas were vote<l to Mr. Peter, 

 Ilr.KEERT, for an improved Book-GafL* 

 Holt, to facilitate the opening of both 

 di;oiH at once, and to fecure the lame, 

 without trouble of bolting two bolts in 

 the common way. It will anfwer equally 

 well for wardrobes, French cafements, or 

 folding falh doors. It will alfl:) make a 

 good fafii fallening, if let into the bottom- 

 fafh, with a fmall brafs knob to Hide as 

 common ; it would bolt in the frame by 

 the fide of the falh cord, both fides at 

 once. 



To Mr. Charles I,e Caatu have been 

 voted ten guineas for an invention of a 

 check to Oarringe-whcels on Rail-roads, 

 which pofiefles the means of preventing 

 thofe various accidents which have from 

 time to time proved fatid to horfes em- 

 ployed in fuch fenice, particularly Avhere 

 tiie declivity is from 12 to 16 inches to 

 the chain and the trafiic principally de- 

 fccnding. 



The ufe of a liorfc employed on a rail- 

 road is as frequently to check the vclocilr" 

 of loaded carriages, as to draw them on 

 Inch part* of the road as are level or near- 

 ly fb. When the horfe finds himfdf 

 prcfi'ed upon beyoiul his power of retift- 

 ance, he is compelled to quicken his pace 

 to relieve himfclf, by which means the 

 velocity of the carriage exceeds his power 

 of maiuigement ; under fuch circum- 

 Itances, the leaft trip of the horfe termi- 

 nates in a fall, by which the animal be- 

 comes injured. As a preventive to all 

 fuch accidents Mr. Le Caan has contrived 

 his check, which may be appropriated to 

 carriages in general. 



The check is fallened by means of a 

 bolt or nut to the fide of the waggon, 

 upon which nut it turns freely, and the 

 other end of the check is fufpended by a 

 chain to the fhalt, \\hLle the horfe is draw- 

 ing ; but if the Ihaft is inclined either by 

 prefVure on the defcending plane, or by 

 accident, the chain fo far gives way, as to 

 fuller the check to clof'e in with the 

 wheel, and thus flop the carriage. 



The inventor recommends a check to 

 each of the four wheels, and thofe behind 

 may occalionally be let down, and ufed 

 as relis to relie\e the horfe when necei- 

 fary. 



The filver medal aud ten guineas have 

 been 



