378 Mr. Pattinson on the Electricity of Steam. 



boiler-house, where was placed a table. The shovel was held 

 by Mr. Smith in the current of steam, with its edge about an 

 inch and a half from the aperture through which the steam 

 issued, and the wire leading away from the shovel was insu- 

 lated by being attached to sticks of sealing-wax held by assist- 

 ants. Mr. Smith stood on an insulating stool. 



7. On touching a pith-ball electrometer, the threads of 

 which were five inches long, with the insulated wire leading 

 from the shovel held as mentioned, the balls diverged four 

 inches with positive electricity. 



8. The wire was attached to an insulated tin conductor, 

 when it yielded sparks half an inch in length. 



9. A pointed wire attached to this conductor exhibited the 

 brush of light a quarter of an inch long, which always attends 

 the escape of positive electricity from a point into the air. 



10. A small jar was now charged so strongly as to give a 

 rather disagreeable shock. By this time a large crowd of 

 men, women and boys from the " Pit Raw," or pitmen's re- 

 sidences near the colliery, attracted by the novelty and singu- 

 larity of the circumstances, had gathered about us, filling the 

 engine-house and looking on with great curiosity and interest. 

 A circle of sixteen of these men and women was formed, and 

 they received together, much to their surprise and merriment, 

 a powerful shock from the charged jar. This was several times 

 repeated, the numbers receiving the shock varying each time 

 from twelve to twenty. 



1 1 . A stout card was perforated by a discharge of the jar ; 

 and cotton wrapped round the end of a copper wire and dipped 

 in pounded resin, readily set on fire. 



12. When the edge of the shovel was made to approach 

 the aperture through which the steam issued as near as three- 

 quarters of an inch, very vivid and bright sparks of that length 

 passed continually between it and the boiler. 



13. The second boiler did not discharge steam through any 

 fissure, but on lifting its valve by the hand it blew off in a 

 strong current. When the shovel was held in one hand in 

 this current of steam issuing from the safety-valve, and the 

 boiler was touched with a penknife held in the other, a spark 

 passed exactly, as under the same circumstances in the boiler 

 subjected to the above experiments. 



From this it would appear that the steam of both boilers 

 was in the same electrical condition. 



During the whole of these experiments the engine was doing 

 its work as usual, occasionally going and occasionally standing; 

 but no difference was observed in the electricity given off by 

 the steam. 



I have been. most careful to supply an exact account of the 



