452 Mr. W. G. Armstrong on the Electricity of Effluent Steam. 



original state. From these observations it would appear that 

 with every flash of lightning the cloud became exhausted of 

 its electricity and recharged itself for each succeeding flash. 



The air in the cloud seems to move from the periphery 

 to the centre, of the nature of a whirlwind, fluctuating with 

 the leaves of the electroscope, and I had sufficient time to 

 witness twenty-one electric discharges from the cloud in which 

 I was immersed, when the wind became so violent, that the 

 instruments were broken, and I was obliged to cling to the 

 stump of a tree to save myself from being blown over the pre- 

 cipice ; but the uproar around me was increasing and fluctu- 

 ating with the electric discharges from the clouds, and the 

 rapid alternations of wet and dry in the clouds, was during 

 the whole time in exact coincidence with the electric dis- 

 charges. 



LXVI. On the Electricity of Effluent Steam. By W. G. 

 Armstrong, Esq. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



]\/|Y letters to Professor Faraday on the remarkable de- 

 ■*-*-*- velopment of electricity which has recently been dis- 

 covered in a jet of steam issuing from a steam-engine boiler 

 in this neighbourhood, having already appeared in your pub- 

 lication, it is, of course, unnecessary for me here to repeat the 

 circumstances detailed in those letters. I shall therefore take up 

 the narrative of my proceedings, relative to this curious subject, 

 at the point at which the second of those letters concludes. 



Having found electricity in all the three boilers I had ex- 

 amined in which water from the neighbouring colliery was 

 used, and not having discovered any indications of it in the 

 boiler which was supplied with rain-water, I was naturally 

 led to believe that the effects I have described were attribu- 

 table to the peculiar nature of the water from which the 

 electrical steam was produced; and, under this impression, I 

 lost no time in visiting some other high-pressure boilers in 

 the same district, which were also supplied with colliery water, 

 strongly impregnated with lime and other mineral matter. 

 The steam from the safety-valves of these boilers also proved 

 to be electrical, but not to such an extent as I had reason to 

 anticipate from the similarity of the circumstances to those 

 under which electricity was developed in such an extraordi- 

 nary degree at Seghill. I then proceeded to try a number of 

 boilers in this town and neighbourhood, in which steam was 



