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XIV. Observations on the Humming Sound produced on Mountains 

 by Electricity. By M. Henri de Saussure*. 



ON the 22nd of June, 1865, leaving Saint Moritz (Grisons), 

 I made the ascent of the Piz Surley, a mountain com- 

 posed of crystalline rocks, of which the somewhat conical summit 

 attains the height of about 3200 metres. During the preceding 

 days the wind had blown steadily from the north, but on the 

 22nd it became variable, and the sky charged with scattered 

 clouds. Towards midday these clouds increased in number and 

 collected together over the highest peaks, elsewhere remaining 

 so high that they did not hide the greater number of the spires 

 and summits of the Engadine, on which soon fell some local 

 showers. Their appearance, that of d ust-like vapours, semi-trans- 

 parent, made us think that they were but showers of snow or frozen 

 sleet (gresil). Indeed, about 1 o' clock in the afternoon, we were 

 ourselves overtaken by a fine hail thinly scattered, at the same time 

 that similar showers enveloped the greater part of the spires of 

 such rocks as the Piz Ot, Piz Languard, &c, and the snowy tops 

 of the Bernina, and that a heavy fall of rain poured down on the 

 valley of Saint Moritz. The cold increased ; and at half-past 1, 

 when we had reached the summit of the Piz Surley, the sleet 

 becoming more abundant, we disposed ourselves to take our 

 repast, and laid our alpenstocks against a little cairn of dry 

 stones which crowns the summit of the mountain. Almost at 

 the same instant I felt at my back, in the left shoulder, a very 

 acute pain like that produced by a pin lightly pressed into the 

 flesh; and when I put my hand there, without finding anything, 

 a similar pain was felt in the right shoulder. Supposing my 

 cloth overcoat to contain pins, I threw it off, but, far from finding 

 myself relieved, I found that the pains increased, extending from 

 one shoulder to the other across the whole back. They were 

 accompanied by pricking sensations and sharp shooting pains, 

 such as a wasp crawling over my skin and covering me with 

 stings might produce. Taking off my second coat, I found no- 

 thing which could wound the flesh. The pain, which was con- 

 tinuous, took then the character of a burn. Without thinking 

 more about it, I fancied, without being able to explain it, that 

 my flannel waistcoat had taken Are, and was about to throw off 

 the rest of my clothes, when my attention was arrested by a 

 sound recalling the reverberations of a diapason. It came from 

 our sticks, which, resting against the rock, sang loudly, emitting 

 a sound like a kettle the water in which is about to boil. All 

 this may have lasted four or five minutes. 



* Translated from the Bibliotheque Universelle for January 15, 1868. 





