Mr. R. Phillips on the Electricities of Steam. 505 



pipe, the negative charge coflected from the steam was the 

 only electrical effect observed. 



nH 99. During the above ex{)eriments the boiler was uninsu- 

 lated, and it was examined at each experiment to be quite 

 certain that the issue of steam communicated positive electri- 

 city to the boiler; this was, however, a needless precaution. 

 These results have been obtained with very different pressures 

 in the boiler, up to 40 lbs. on the inch. The statement (4-8.), 

 that at 40 lbs. on the inch the boiler is positive at a certain 

 pressure, and negative at lower, is an error, into which I fell 

 probably through not being aware of the influence of water 

 (74. 114.). Although I experienced considerable difficulty at 

 first, I can, now that the conditions are better known, make 

 the boiler positive with the same precision, whether the pres- 

 sure in the boiler is 6 or 40 lbs. on the inch. 



100. 1 have sometimes observed the .electricity of the water 

 as it issued from the fountain to be negative ; at such times the 

 electricity apparently given by the steam in the tin pipe, was 

 negative when the steam was turned on, and positive when it 

 was shut off, the general |irrangement of the apparatus being 

 as before. 



101. The following is, I think, the explanation of these 

 results : — When the fountain is insulated and a current of elec- 

 trified water is passing from the jet, the fountain soon takes 

 its maximum electric charge, the issuing stream of water being 

 oppositely electrified ; and the electric difference between the 

 water and the brass jet being so great, that the electricity 

 generated by the friction runs back again through the water 

 to the brass jet. If now a medium possessing greater induc- 

 tive capacity than air be made to surround the stream of 

 water, the electric difference between the issuing water and 

 the brass jet is diminished, and electricity is again carried 

 forward by the water ; and the same quantity of opposite elec- 

 tricity is accumulated on the brass fountain. When air is 

 again made to surround the jet of water, the excess of electri- 

 city which the former medium had caused to be accumulated 

 on the fountain, passes off" by the jet of water. I thus come 

 to the conclusion that the specific inductive capacity of the 

 steam-cloud is much greater than air. It is now necessary to 

 separate these experiments with the fountain from those of 

 the electricity of condensation. ^ 



102. The hole in the bung was reduced to a circular aper- 

 ture, '6 inch diameter, and the distance of the aperture Irom 

 the end of the brass jet of the boiler was TS inch, every- 

 thing else being as before (95.). The positive electricity when 

 the steam was turned on, and the negative when it was shut 



Phil. Mag. S. 3. No. 246, Suppl. Vol. ^Q. 2 L 



