Hydro-electric Machine. 



197 



glass after having been filled with a portion of the liquid con- 

 tained in it. The tubes were all of the same size, being three 



Fig. 3. 



Distilled water 



Distilled water 



Distilled water acidified with one-sixth of its \ 

 volume of sulphuric acid / 



Distilled water acidified with one-sixth of its 

 volume of sulphuric acid 



Solution of sulphate of soda reddened with "1 \ ^ ^^- '■ 

 acidified litmus / 



Solution of sulphate of soda coloured blue 

 with litmus 



Solution of sulphate of magnesia reddened "I v 

 with acidified litmus J 



Solution of sulphate of magnesia coloured"! \ 

 blue with litmus J 



Distilled water reddened with acidified litmus 



Distilled water coloured blue with litmus 



inches and a half long and one-sixth of an inch wide in the 

 inside. The platina wire of the first tube was connected with 

 the boiler, and that of the last with a discharging train, con- 

 sisting of a lead pipe which passed into a neighbouring well. 

 The wires of the other tubes were connected in pairs, and wet 

 cotton placed between every alternate glass, as shown in the 



