Curiosities of Science. 115 



The depth of the Grenelle Well is nearly four times the height of 

 Strasburg Cathedral ; more than six times the height of the H6pital 

 des Invalides at Paris ; more than four times the height of St. Peter's 

 at Rome; nearly four times and a half the height of St. Paul's, and nine 

 times the height of the Monument, London. Lastly, suppose all the 

 above edifices to be piled one upon each other, from the base-line of the 

 Well of Grenelle, and they would but reach within 11 feet of its surface. 



MM. Elie de Beaumont and Arago never for a moment doubted the 

 final success of the work ; their confidence being based on analogy, and 

 on a complete acquaintance with the geological structure of the Paris 

 basin, which is identical with that of the London basin beneath the 

 London clay. 



In the duchy of Luxembourg is a well the depth of which surpasses 

 all others of the kind. It is upwards of 1000 feet more than that of 

 Grenelle near Paris. 



HOW THE GULF- STREAM REGULATES THE TEMPERATURE OF 

 LONDON. 



Great Britain is almost exactly under the same latitude as 

 Labrador, a region of ice and snow. Apparently, the chief 

 cause of the remarkable difference between the two climates 

 arises from the action of the great oceanic Gulf-Stream, whereby 

 this country is kept constantly encircled with waters warmed 

 by a West- Indian sun. 



Were it not for this unceasing current from tropical seas, London, 

 instead of its present moderate average winter temperature of 6 above 

 the freezing-point, might for many months annually be ice-bound by a 

 settled cold of 10 to 30 J below that point, and have its pleasant summer 

 months replaced by a season so short as not to allow corn to ripen, or 

 only an alpine vegetation to flourish. 



Nor are we without evidence afforded by animal life of a greater 

 cold having prevailed in this country at a late geological period. One 

 case in particular occurs within eighty miles of London, at the village 

 of Chillesford, near Woodbridge, where, in a bed of clayey sand of an 

 age but little (geologically speaking) anterior to the London gravel, Mr. 

 Prestwich has found a group of fossil shells in greater part identical 

 with species now living in the seas of Greenland and of similar latitudes, 

 and which must evidently, from their perfect condition and natural 

 position, have existed in the place where they are now met with. Lec- 

 tures on the Geology of Ctapham, &c. by Joseph Prestwich, A.R.S., F.G,S. 



SOLVENT ACTION OF COMMON SALT AT HIGH TEMPERATURES. 



Forchhammer, after a long series of experiments, has come 

 to the conclusion that Common Salt at high temperatures, such 

 as prevailed at earlier periods of the earth's history, acted as 

 a general solvent, similarly to water at common temperatures. 

 The amount of common salt in the earth would suffice to cover 

 its whole surface with a crust ten feet in thickness. 



FREEZING CAVERN IN RUSSIA. 



This famous Cavern, at Ithetz Kaya-Zastchita, in the Steppes 



