490 Mr. R. Phillips on Electricity and Steam. 



conical one, has its x and y dependent on the periodic cos ju. ; 

 which quantity enters explicitly and implicitly in the differen- 

 tial expression for the centripetal force to the focus, which is 

 therefore uot identical with the Newtonian law. 



S. M. Drach. 

 November 26, 1849. 



LXI. On Electricity and Steam. i?j/ Reuben Phillips, £.sy.* 



35. ^T^HIS paper is a continuation of a former one (Phil. 

 A Mag., vol. xxxiv. p. 502), wherein are described 

 some magnetic actions produced by steam in the act of con- 

 densation. 1 regarded those motions as the effect of dynamic 

 electricity, and then endeavoured to obtain the static effect, 

 which I think I have done. 



36. An electrometer was constructed in the following man- 

 ner: — A straight slip of thin metal, about '4 inch wide, was 

 bent at some distance from one end, the direction of the mo- 

 tion in bending being in a plane perpendicular to the original 

 surface of the plate and parallel to its length, and the bending 

 was continued until the included angle was 0; the bend was 

 opened a little, the end of a slip of gold-leaf inserted, and the 

 whole rendered secure with a binding-screw. Previously, 

 however, the plate at that part which was close to the end 

 that had been doubled in, had been bent in the same direction 

 as before, four times at right angles, so as to leave a little pro- 

 jection across the plate, over which the gold-leaf hung; the 

 object being to keep the gold-leaf so far from the metal plate, 

 that a rapid inspection sufficed to show that the former was 

 free to move. The gold was the length of one side of the 

 usual gold-leaf, and the metal plate extended parallel with it 

 to its lower end. The doubled portion was now fitted into a 

 slit in a cork, which was then inserted into a glass tube, the 

 end of the bent portion projecting about | inch beyond the 

 external end of the cork. The other end of the glass tube 

 also held a coi'k, through which a straight metal plate passed 

 extending parallel to the gold-leaf. The tube was about -9 

 inch diameter and 5^ inches long, and the ends were covered 

 with sealing-wax; however, care was always taken to connect 

 the plate of the lower cork with the earth. The whole could 

 be supported on a small wooden stand. 



37. A singular appearance, but not connected with elec- 

 tricity, is presented by this electrometer when either of the 

 metal plates is made to vibrate, as by a slight tap ; for the 



* Communicated by the Author. 



