Scientific hitelligence. — Meteorology. 417 



meteorology. If they remain in Finmark, at Kielvik, at Ham- 

 merfest, or at Alten, whose mean temperature is below the freez- 

 ing point, they ought to investigate why water never freezes 

 in well closed caves ? The stream of Hammerfest, which, ac- 

 cording to M. de Buck, never ceases to flow in the midst of win- 

 ter, will also engage their attention ; finally, they will not fail, 

 were it only by making use of the simple holes which are made 

 by the miners' borer, to examine how the temperature of the 

 earth varies daily at different depths. These observations, I 

 believe, have never been made in regions where, for whole 

 months, the sun never sets. Thus, these observations will be 

 an interesting acquisition for science, independently of their * 

 possible connection with the anomaly in the terrestrial tempe- 

 ratures, to which I have especially wished exclusively to devote 

 these remarks. — Arago."' 



2. Depth of the Frozen Ground in Siberia. — At page 435 

 of vol. 24th of Edinburgh New Philosophical Journal, we in- 

 8erted Professor I3aer*s communication to the Geographical So- 

 ciety of London, " On the Frozen Soil of' Siberia.''^ We have 

 now to add, that a further communication on this subject, also 

 by M. Baer, was read at the meeting of the British Association 

 at Newcastle. After stating very shortly the nature of the ex- 

 periments to be made at Yakutsk by order of the Petersburg!! 

 Academy of Science, he remarks, " It seems to me very import- 

 ant for physical geography, to ascertain the thickness of per- 

 j)etually frozen ground in countries whose mean temperature is 

 considerably below 0^ R, I will merely mention one point : if, 

 as is the case at Yakutsk, the ground never thaws at the depth 

 of from 300 feet to 400 feet, all the small streams whose super- 

 ficial waters only are kept in a fluid state in the summer, must 

 be in the winter entirely without water ; and, vice versa^ we 

 may conclude that all rivers which do not come far from the 

 south, and whose course is entirely within those countries which 

 preserve perpetual ground-ice, and yet do not cease to flow in 

 winter, must receive their waters from greater depths than those 

 which remain in a frozen state. It is, then, clear that these 

 veins of water penetrate the perpetual ground-ice. This cir- 



• The notices with signature Armjo were drawn up by that philosopher 

 for the use of the French Scientific Expeditions, at present in the north of 

 Europe, and in Northern Africa. 



