104 Mr. R. Phillips on the comiexion of the Electricity of 



valve, which admitted of a pressure being maintained in the 

 boiler eqiinl to about 6 lbs. on the inch; everything else was 

 as before (4'8.). The boiler was connected with the single- 

 leaf electrometer. When the cock was opened a little, so 

 that the steam might escape from the brass jet with very little 

 force, probably a few ounces on the inch, the boiler became 

 feebly positive. On opening the cock more, the positive elec- 

 tricity of the boiler became stronger until the pressure at the 

 jet was increased to what I estimated to be about 3 lbs. on 

 the inch ; afterwards the positive electricity of the boiler be- 

 came less, and at 6 lbs. on the inch the boiler was strongly 

 negative. 



72. The larger collector was placed in the steam at a di- 

 stance of about 6 inches from the brass jet, and united with 

 the single-leaf electrometer. Many of the lower pressures 

 which readily made the boiler positive did not cause the 

 steam to give any electricity to the electrometer; but when 

 the pressure was increased to 2 or 3 lbs. on the inch, a nega- 

 tive charge was given to the electrometer. The negative state 

 of the steam, like the positive state of the boiler, went on in- 

 creasing, within certain limits, with the pressure. The boiler 

 was always positive when the steam was negative. 



73. When the pressure was increased to a degree a little 

 lower than that at which the boiler changed from positive to 

 negative, the steam communicated a positive charge to thecol- 

 lectoi', even at a distance of a foot from the end of the brass jet. 



74. The Armstrong's condenser with water, beinj; inter- 

 posed between the boiler and jet, did not much alter the above 

 effects; however, I think I may certainly say that the boiler 

 changed from positive to negative at a lower pressure than it 

 did without the condenser. When the boiler was positive, the 

 sound of the steam was a smooth hiss; but as the pressure 

 was increased it changed to a roar, the boiler becoming at the 

 same time negative. With a very feeble roar the boiler was 

 neutral, which neutrality I have occasionally observed without 

 the condenser. The steam was also found to be negative as 

 before ; I did not however try to make the steam and boiler 

 both positive with this arrangement. 



75. The gun-barrel and brass tube were placed before the 

 jet as formerly (58.), and connected with the boiler and single- 

 leaf electrometer, the steam being at about 6 lbs. on the inch. 

 When the cock was fully opened, the electrometer was power- 

 fully acted on by positive electricity ; and on holding the large 

 collector in the steam and then bringing it to this electrometer, 

 it also communicated a positive charge. In order to produce 

 these effects, it was necessary that plenty of water should be 



