ELECTItltJAX MACHINE. 1Q!7 



producing -an IntenCe degree of eledhicity. It is true, that Rubbing the 

 it has heen propofed to apply the amalgam to the glafs in- g^^ inftead of 

 iiead of the rubbers ; but the greater effeft, that feems to be the rubbers a bad 

 produced by this laft method, is only apparent, and confifts "^^^ 

 entirely in the circulation of the fluid on the glafs, while far 

 from exciting or accumulating more of the fluid, this procefs 

 and the circulation difperfe it. 



4. The amalgam on the leather docs not require to be fre- The amalgam 

 quently renewed. The duft of the amalgam, that is depofited f^g^g^^^j. [gJcw! 

 on the edges of the paper, is injurious only when accumulated ing. 



there in fufficient quantity to be conveyed to the glafs, from 

 which however it may eafily be removed. 



5. The return and pafTage of fparks to the rubbers are The return and 

 rendered more difficult, as the paper fufficiently covers the ^ th? rubb^e^ 

 borders of the rubbers, that are turned toward the axis. more difficult, 



6. In my conftrudion the rubbers may be larger than in the The rubbers 

 Hfual way, and in reality they are larger in proportion in my '"^■^ ^ ongcr. 

 machine than in Van -Mar urn's. No fpark pafTes the axis, ^P^rks do not 

 unlefs the air be very damp ; for the fluid, in cafe of a ftrong 

 accumulation, flies in preference to the oppofite rubber over 



a quarter of the periphery of the glafs. I am perfuaded, that, 



by adopting my conftru6tion, the rubbers of a plate of 32 



inches, fuch as Van-Marura's is, may be eleven inches in- 



ilead of nine, in which cafe there would ftill be two inches 



for the diameter of the piece of wood that fattens the plate 



to the axis, and three inches for the difi:ance from this piece 



to the rubbers; which I think would be fufficient in thefe 



circumflances ; and the fridion being on a larger furface of 



the plate, the effect mufl naturally be much greater. I fliall farther triah 



try this alteration of the rubbers on large plates of Bohemian 



glafs, as well as on Englifli cylinders of 18 inches diameter, 



and 'J I inches long. The refult I have already obtained with 



afmall cylinder gives me reafon to hope much more complete 



fuccefs with a large one. 



7. With my rubbers the fridion may be rendered much The friaion 



greater, than with thofe the amalgam of which is in immediate ^^y^^"^^'^^ - 

 1 1 /• » much greater, .i 



contact With the glafs, and foils it; befides, the plate turns and is uniform, 

 with an uniform friction. 



8. The aaivily of the machine is extraordinarily increafed '^^^ a^iyity of 

 by this coiiftruaion. The greater fr^fedom with which the traoJdfnarily hiT 



plate creafcd, and 

 whv. 



