On the supposed Morames of Glaciers t7i Scotlaiul. 337 



think is inevitable, that the electricity vvhich is excited in the 

 evaporating vessel on the emission of steam, is independent 

 of concomitant evaporation. 1 should observe, that the elec- 

 tricity which appeared in the boiler after, as well as shortly 

 before, the exhaustion of the water, was x\n\^ovm\y positive. 



Under these circumstances, I think there are certainly 

 grounds for supposing that the same cause which excites 

 electricity in the steam-cloud, produces also the contrary elec- 

 tricity of the boiler ; but if this be so, I am not aware that there 

 is any known principle u{)on which the effects can be ex- 

 plained, especially as the electricity of the boiler appears 

 quite independent of the proximity of the jet. 



The transmutation which, under certain conditions, takes 

 place in the electrical states of the boiler and steam-cloud, is 

 a part of the subject embarrassed with difficulty. What 

 possible change can the steam undei"go in the boiler, either 

 by contact with heated metal, or otherwise, which can cause 

 il to evolve, on its subsequent condensation, the opposite 

 electricity to that which it usually liberates? 



The effects of pressure appear equally inexplicable. It seems 

 inconceivable to me that steam should acquire by pressure any 

 property which would not be taken away by expansion, and yet 

 we find that the influence of pressure in the boiler, upon the 

 electricity of the jet, is not destroyed by suffering the steam 

 to dilate before it is ejected. 



I fear this paper has extended to a somewhat tedious length, 

 and I shall therefore conclude it here by expressing a hope 

 that what has been stated may have the effect of stimulating 

 inquiry into the curious subjects of which I have treated. 



Wm. Geo. Armstrong. 



LVI. On the supposed Moraiiies of Ancient Glaciers in Scotland, 

 lii/ William Kemp, Esq., introduced by a Letter from J. E. 

 Bowman, Esq., F.L.S. 



[Illustrated by Plate III.] 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 



IVf 11. KEMP, of Galashiels, having flavoured me with a 

 -'-*-*- copy of a paper lately drawn up by himself^ containing 

 new proofs of the former existence of glaciers in Scotland, I 

 thought it desirable that they should be generally known, be- 

 cause I am aware that some of my ablest geological friends are 

 waiting for further evidence (and wisely so) before they adopt 

 Phil. Mag. S. 3. Vol. 18. No. 118. Majj 18tl. Z 



