§ 854-856. 



THE ANTARCTIC REGIONS, ETC. 



455 



854. In the southern hemisphere — and our attention is now di- 



The rarefaction of the Tccted exclusivelj to that — the polar winds on the 

 air over polar region., g^^^^j^ g'^j^ ^^ ^Qo ^^^ ^^^^ ^^^^ Stronger than are 



the equatorial winds on the north side of 35° : a fact indicative 

 of a greater degree of rarefaction about the place of polar calms 

 than we have in the equatorial calm belt. 



855. That such is the case is also suggested by the fact that 

 Barometrical observa- thc iudraught iuto the autarctic calm place is felt 

 "*'^'- (§ 854) at the distance of 50° from the pole all 

 round, while the equatorial indraught is felt no farther than 85° 

 from the equator ; and that such is the case is proved by the ba- 

 rometer. Lieutenant Andrau, of the Meteorological Institute of 

 Utrecht, has furnished us from the Dutch logs with 83,334 observa- 

 tions on the height of the barometer between the parallels of 50° 

 N. and 36° S. at sea. Lieutenants Warley and Young have ex- 

 tracted from the log-books of this office, taken at random, 6945 

 observations on the barometer south of 40° at sea. Dr. Kane has 

 furnished us with the mean height of the barometer in lat. 78° 

 37^ N., according to 12,000 hourly observations made during 

 his imprisonment of 17 months in the ice there. The annals 

 of Greenwich and St. Petersburg give us the mean height of the 

 barometer in lat. 51° 29' N. according to three years' observa- 

 tions, and in lat. 59° 51' N. according to ten years of observa- 

 tion. Such are the sources of the following table : 



Mean Height of the Barometer. 



• Maandelijksche Zeibaanwijzingen van Java naar Het Kanaal. Als Uitkomsten Wetenschap en 

 Ervaring Aangaande Winden en Zeestroomingen in Sommige Gedeetten Van Den Oceaan Uitgegenen 

 Door Heet Koninklijk Nederlandsch Meteorologische Institut. t'trecht, 1859. 



t The mean height of the barometer for England generally is 29.94°. — Admiral Fitz Roy. 



856. Cnptains Wilkes, U. S. X., and Clarke Eoss, R. K, both, 



