72 Proceedings of Philosophical Societies. [July, 



This law is, that the square of the temperature of a given portion 

 of gas varies as the elasticity and volume conjointly; and, 

 therefore, when either continues the same, the temperature is as 

 the square root of the other. 



Hence Mr. Herapath finds, that the heat of boiling water is 

 to that of melting ice as \/ 1 1 to -/ 8, or as 1*1726 to 1 nearly ; 

 and the point of absolute cold he also determines in a manner 

 independent of any theory of heat, from the principle of an air 

 thermometer. 



These experiments agree precisely with a theory given by 

 Mr. Herapath in the paper which he has just published in the 

 Annals, on the Causes, Laws, Sec. of Heat, Gases, and Gravita- 

 tion, written many months before he undertook the experiments 

 in question. 



Junel . — On the Remeasurement of Sir J. Shuckburgh's Cube, 

 Cylinder, and Sphere, by Capt. Kater. 



June 21. — On the Parallax of the Fixed Stars, by Dr. 

 Brinkly. 



GEOLOGICAL SOCIETY. 



March 16. — The reading of Mr. Strangway's paper on the 

 Geology of Russia was continued. 



From the Baltic Isles, through Esthonia, the north of Livonia 

 and Ingria, up to Vitegra, at the south-east corner of Lake Onega, 

 a strong and regular series of secondary rocks is observable. 

 The lowest is a pale greenish blue clay, which is surmounted by 

 sand or sandstone, alternating in the neighbourhood of Peters- 

 burg, with beds of shale. Above this a thick bed of limestone 

 occurs, which is characterised by the same fossils that mark the 

 limestone of Sweden and Norway, according to Von Buch. 



The northern salt district stretches in a line parallel to the 

 Petersburg limestone above-mentioned for 1000 versts, and 

 makes its first appearance in the isle of Osel. It is worked in 

 some parts of Livonia. Gypsum is also quarried in some places, 

 and exported in large quantities to Petersburg from Riga. It is 

 capable of a high polish, and much resembles the oriental ala- 

 baster; but true alabaster has only as yet been found at Osel. 



On the south side, the valley of Novgorod is bounded by the 

 ridge of the Vasday hills, which, though they form the principal 

 chain between the Baltic and the Black Sea, yet do not exceed 

 800 or 900 feet in height. Their escarpment is greatest towards 

 the north. All the chief rivers of Russia rise from them. Near 

 the town of Boravichy, which is situated at the foot of the Valday 

 hills, are the falls or rapids of Nista; and as the river, for nine 

 or ten miles above the town, runs between lofty and precipitous 

 cliffs, excellent sections of the stiata are exposed. Where the 

 first ridge of hills abuts against the stream, is a lofty perpendi- 

 cular cliff, of which the upper part consists of a pale reddish 

 sand, presenting patches of a bright yellow colour towards the 



