Compound electrical instrument. X^ 



IV. 



befcription of a corn-pound Electrical Irifirument for condenfing 

 and doubling : xvith Experiments. j5j/ Mr. Wilson. 



London, Augufi 10, 1804. 



To Mr. NICHOLSON, 

 SIR, 



1 TAKE the liberty of troubling you with the following ac- Compound 

 count and drawing of a compound condenfer of eleflricity, eleftncal can» 

 which I think is an improvement on Cavallo's multiplier of 

 ele<5lricity, defcribed in his Treatife on Ele^ricity in the 



third volume, of the fourth edition, and if you think it worth 

 a place in your Philofophicil Journal, yoii will vfery much 

 oblige me by inferting it therein. 



I am your obedient 



Humble fervant, 



W. WILSON. 



The drawing is an exa6l reprefentation of the inftrument, Defcription and 

 about half its real fize, (Plate 3 J The plates A, B, C, D, !^''^^i"g °f, ^« 

 and E are fupported by glafs flicks, covered with fealing wax 

 at the upper part ; but the plate F is fupported by a wire, 

 which has a joint at the bottom, by which it may be brought 

 near the plate E, or thrown back away from it. 3 is a fcfew, 

 which Hops againft the glafs fupport of E, and regulates the 

 diftance of the two plates when one is brought near the other. 

 The plates A, C and E are fixed to the bottom board, and B 

 and D to the levers L 1, which move round the pins p p, and 

 and areconneded by the rod R. It will be feen by the draw- 

 ing, that when the lever L is moved, the plates B and D are 

 moved in contrary dire6lions> that is» they both approach to- 

 'Wards or recede from the plate C at the fame time, but on op* 

 pofi te fides* The faces of the plates are ground flat, and they 

 are fo adjufted that if the fcrews 2 2 did not flop the levers 

 when they are moved, the face of B would flop flat againft the 

 face of A, and fo would the face of D againft C. The fcrews 



2 2 ftop them when at a very fmali diftance, which may be 

 made more or lefs by turning the fcrews. 



C-2 '. This 



