176 EXPERIMENTS ON THE ELECTRIC PILE. 



Extreme velocity Thefe experiments have farther proved in a decifive man- 

 o t e fluid. ner ^ an( j Qn a j ar ^ e ^ a j e ^ anot j ier important circumflance re- 

 specting the pile ; namely, that the ftream of fluid moved by 

 it has a velocity furpaffing all conception ; fince a battery of 

 137f lquare feet was charged to the intenfity it difplayed by 

 a contact as fliort as poffible with the wire of communication, 

 a contact that did not continue one-twentieth of a fecond^ 



Hence the effects After this it is no way aftonifhing, that the pile, by a con- 

 of the pile fupe- ,. r . _. J n . .- °. _ , * _ J . 



rior to thofe of tinuance of its action, mould produce iuch effects as have 

 common electri- never been [een where common electrical machines are em- 

 mac nnes, pi y e( ^ as tne fp ee( |y decompofition of water for inftance. 

 Certainly no other electrical machine known, the grand 

 Teylerian machine excepted, can furnifh a continued ftream 

 and may be of at all approaching that of the .pile ; on which account it is a 

 | cs# p y powerful mean of producing feveral effects, which may con- 



tribute greatly to the progrefs of natural philofophy. 

 Method of in- This confideration induced Dr. Van Marum to endeavour 

 fulating the pile. to augment the power of the pile. From the beginning he 

 was careful to iiifulate it more effectually than is commonly 

 done. For this purpofe he placed it on a thick cake of lac, 

 and kept it in its vertical pofition by flicks of fealing-wax 

 two inches long, fixed horizontally in four flips of wood, 

 lurrounding the pile. Thefe flicks of fealing-wax were fixed 

 to little wooden cylinders, paffing through holes in the up- 

 rights at every four inches, and kept in their places only by 

 being made to fit with fuch a degree of tightnefs, as would 

 allow them to be moved backward or forward, fo as to fuit 

 piles of different diameters. The uprights were fixed at top 

 and at bottom in a piece of wood a foot fquare. Profeflbr 

 Pfaffhimfelf was aflonifhed at the great effect of the firfl pile 

 compofed of three Guilder pieces, plates of zinc of the fame 

 diameter, being an inch and a half, and bits of cloth moiflened 

 Wire fufed by it. with a faturated folution of muriate of ammoniac. In one of 

 the experiments the end of an iron wire, No. 16, T % ru of an 

 inch in diameter, was made red-hot for the length of a line, 

 and even fufed at the extremity, by a pile of fixty pairs. 



Having read an account of the experiments of Fourcroy, 

 Vauquelin, &c. on the fufion of wire by large plates of cop- 

 per and zinc, Dr. Van Marum procured thirty-two of each 

 metal, five inches fquare, and made a pile with them ; firll 



of 



