504 Mr. R. Phillips oti the Electricities of Steam. 



tubes were varnished externally with a solution of sealing- 

 wax. The longer arm of the tin pipe was placed perpendicu- 

 larly to the horizon, with its mouth upwards ; the other arm 

 of the pipe stood before the brass jet of the boiler (40.), as 

 formerly (83.). The tripod stand was placed near the tin 

 pipe, and the fountain (77.) placed upon the tripod. The cock 

 of the fountain was fitted with a straight glass tube, except 

 that near its upper end the glass tube was bent twice at a 

 right angle in the same plane ; this end of the glass tube held 

 a brass jet, through which the water was projected downwards 

 about the axis of the long arm of the tin pipe. The distance 

 of the brass jet of the fountain, from the nearest part of the 

 tin pipe, was 1 1 inches ; and the diameter of the aperture of 

 the brass jet of the fountain was -jy^ inch. 



95. The fountain was now electrically connected with the 

 ground, and the tin pipe with the single-leaf electrometer. The 

 cock of the fountain was opened a little, so that the water was 

 discharged from the jet by some low pressure, perhaps equal 

 to 6 or 10 vertical feet of water; a positive charge was com- 

 municated to the electrometer. The cock of the boiler was 

 now opened so as to make the boiler positive ; a great increase 

 of positive electricity was immediately given to the tin pipe, 

 the gold-leaf being kept in contact with, or rapidly striking 

 the conducting plate of the electrometer; and this effect con- 

 tinued without diminution so long as the supply of steam 

 and water was maintained. This result is^ identieal ^witli that 

 previously obtained (84.). ■ ^gjjid .;i5 bctfc 



96. The fountain was now insulated; the cock of the foun- 

 tain being opened as before, the positive charge, which at first 

 was freely given to the electrometer, soon became very feeble 

 (it could be immediately renewed by touching the fountain) : 

 then opening the boiler as before, a quantity of positive elec- 

 tricity passed through the electrometer ; presently this effect 

 also ceased, and then the electrometer generally began slowly 

 to discharge itself of negative electricity. The steam was 

 now shut off; then, as soon as the steam began to leave the 

 tin pipe, the gold-leaf commenced rapidly striking the con- 

 ducting plate with negative electricity; in aJew secojads this 

 negative charge was exhausted. -in ?t bLfob 



97. The negative electricity which the instrument slowly 

 acquired in this experiment, after the positive effect was over 

 and while the steam was passing, was no doubt merely the 

 negative electricity collected from the steam (81.). 



98. The fountain and tin pipe were now electrically united ; 

 on opening the cock of the fountain as formerly, no electricity 

 was produced ; and when the steam was sent through the tin 



