ACCOUNT OF A CURIOL'S PHENOMENON, ' 20T 



tlie fide oppofite to the chimney; immediately above this 

 courfe o( bricks, thofe which Cucceed muft be removed four 

 inches from the copper, and continue i^o to the height of four 

 inches; afterwards each courfe of bricks muft be brought 

 nearer, fo that this refer voir of heat may be clofed at the 

 height of five inches, which muft be done round all the cir- 

 cumference of the copper. 



K is the opening of the chimney : it muft be three deci- 

 metres fquare through all its height, and at leaft four metres 

 high. 



' L is a blower of hammered iron ; it is one metre above the 

 copper, and ferves to open or clofe the chimney at pleafure. 

 ' The proportions laid down in this plan are intended for a 

 copper four feet three inches wide in its lower part, anti 

 forty inches deep. 



XV. 



Jn Account of a cunous Phenomenon obferved on the Glaciers of 

 Chatnouny ; together with fome eccnfional Obfervations con- 

 cerning the Propagation of IJeat in Fluids. By Benjamin 

 Count of Romford, V. P. R, S. Foreign AJfociate of the 

 National Injiitute of France^ Sfc. SfC. * 



In an excurfion which I made the laft fummer, in the month Cyllndncal pit 

 of Auguft, to the Glaciers of Chamouny, in company with ('"^ "^^^^ °''.^'^* 

 ProfeflTor Pictet of Geneva, I had an opportunity of obferving, j^g water. 

 on wiiat is called the Sea of Ice, (Mer de Glace,) a phenome- 

 ncMi very common, as I was told, in thofe high and cold regions, 

 but which was perfc ftly new to me, and engaged all my atten- 

 tion. At the furface of a folid mafs of ice, of vaft thicknefs 

 and extent, we difcovered a pit, perfedly cylindrical, about 

 feven inches In diameter, and more than four feet deep; quite 

 full of water. On examining it on the Infide, with a pole, I 

 found that its fides were polillied ; and that its bottom was he- 

 mifpherical, and well defined. 



This pit was not quite perpendicular to the plane of the 

 borizon, but inclined a little towards the fouth, as it de- 



\ 



PhiL Tranf 1804, p. 23. 



fcended ; 



