64 ANNUAL KECORD OF SCIENCE AND INDUSTRY. 



was exhibited, until forty-five pounds were required to keep 

 the equilibrium. Suddenly the revolutions ceased, and the 

 lead was found to have reached bottom at the extraordinary 

 depth of 2700 fathoms, or about 100 fathoms greater than the 

 deepest hitherto indicated upon the charts. 



PHYSICAL GEOGRAPHY OF THE BED SEA. 



The Hydrographic Office has lately published a pamphlet 

 on the physical geography of the Red Sea, translated from 

 the German of Captain W. Kropp, of the Imperial Austrian 

 navy. The article contains an account of the formation of 

 the coast, the winds, the clouds, the amount of atmospheric 

 precipitation, the temperature and pressure, the saltness and 

 temperature of the sea, the currents, tides, depths, etc. The 

 tables of temperature given well bear out the reputation of 

 the Red Sea in regard to excessive heat, the maximum tem- 

 perature ranging from 80 in November to nearly 105 in 

 July ; and the minimum in November and December being 

 about 58. This temperature in itself, although indicating 

 one of the hottest regions on the globe, would not be unbear- 

 able were it not for the enormous amount of moisture in the 

 atmosphere, which makes it a perpetual hot bath. 



The Red Sea is an exception to the general rule that deep 

 water approaches close to high and rocky shores, while a low 

 and flat shore indicates shallow water. Although the sea is 

 surrounded almost entirely by a flat sandy coast, the depth 

 of the water up to the land is very considerable. The de- 

 scent is gradual in a few localities, the bottom of the sea 

 forming plateaus, with sudden and steep descents from one 

 to the other in some cases. 



CHANGE OF LEVEL IX THE NORTHERN SEAS. 



According to Notice, No. 89, just published by the Hydro- 

 graphic Oflice at Washington, the principal results of the ex- 

 plorations in the Northern seas about Nova Zembla during 

 the past year prove that the waters are completely free from 

 ice for five months in the year, during which period they are 

 navigable alone: the northwest coast of the island as late as 

 September, while the sea east of it was not only free from ice, 

 but had a temperature of about 48 Fahr. in the month of 

 September. The position and contour of Nova Zembla on 



