Ele^rlcai Muchlfle sperat'tiig h^^the Frisian ofSifk, 4*t 



«ppc3r to be corifiderable, I have thought it of advantage to Ihrert the defcription of the 

 latter in this plafe. 



A, B, n. XVlII. is a wooden table four feet and a half long, two feet nine inches wide, 

 and fomewhat more than an inch and a half thick : its feet are 1 8 inches long. Upon 

 this table are faftened by ftrong wooden fcrews, a h c d, two crofs pieces, each nine 

 inches broad, which carry the uprights C, D, E, F, which laft are 27 inches in height. 

 At about two-thirds or more of the height of thefe uprights, there are cut notches of an 

 inch fquare each, in which tlie axes of the two cylinders G and H turn freely. Thefe 

 axes are parallel to the table and to each other, and are kept in their place by clamps of 

 wood fcrewed over them. The cylinders G and H are formed of light wood glued 

 together, and covered at the ends by a circular piece, whofe rounded edges arife half an 

 inch above the furface of the cylinders themfelves. Their diameter is eight inches ; the 

 axes are of box wood, and are lefs than an inch in diameter, having a fhoulder which 

 prevents the ends of the cylinders from touching the uprights when turned round ; and 

 laftly, the cylinders are covered with ferge. 



The handle is copper, its radius being fix inches long. 



K, L, is a piece of tafFety covered witji oily and refinous matter, of the fame kind as is 

 ufed in France in the conftruflion of air-balloons, which, M. Rouland fays, renders the 

 Clk very ele£l;rical : the breadth of the filk is nearly one inch lefs than the length of the 

 cylinders, and it is wrapped round them with its ends fewed together. 



The whole breadth of the filk is taken hold of or pinched between two flattened tin tubes 

 oppolite each other at M, and two of the fame kind at N : thefe are the rubbers, and may 

 be made to prefs againft each other, more or lefs ftrongly, by means of fcrews. They arc 

 retained by firings of filk faftened to the four uprights of the machine, v v are two brafs 

 chains hooked upon the rubbers, and communicating with the earth ; op and q r are four 

 pieces of tafFety, prepared in the fame manner as the principal piece, fewed in the dire£lion 

 of their length to the rubbers, and faftened to each other by their correfponding corner* 

 by means of threads of filk. The metallic tubes or rubbers are covered with cat's flcin. 



S reprefents the conduftor. It is a cylinder of brafs thrge inches in diameter, 36 

 inches in length, including the balls at the end, whofe diameters are four inches : one of 

 thefe balls has a ring, t, above it, which ferves to form a communication between the 

 conduftor S and any other condudor. 



The upper and lower parts of this cylindrical prime conduflor are armed with two 

 plates of brafs ^;i, whofe length is equal and correfpondenc to the breadth of the taffety, 

 which is 16 inches, aiid 132 inches or 1 1 feet long : the edges of the plates are abctit half 

 an inch dlftant from the filk, and ferve inftead of the metallic points that were ufcd by 

 M. Walckiets, but rejedted by M. Rouland, becaufe they were apt to ftick into the 

 filk and damage it. 



of the cylinders. The inventors have given no inftruftions to obviate this defeft. I have no doubt but that 

 they made their rollers gradually largeft in the middle. 1 have fecn a machine for folding woollens, invented 

 and made by Mr. Rehe, of Shoe-lane, in which this difficulty was removed in fomc leading rollers, by making 

 them in the form of two very acute frnftums of cones, joined at the middle by the larger bafc. — See Phil. 

 Journal, I. 13. 



Vol. IL—Dec. 1798. 3 I The 



