THE ANTARCTIC REGIONS AND THEIR CLIMATOLOGY. 



455 



in the ice there. The annals of Greenwich at St. Petersburg give 

 us the mean height of the barometer in lat. 51° 29' N., according 

 to three years' observations, and in lat. 59° 51' N., according to 

 ten years of observation. Such are the sources of the table. 



* Maandelijksclie Zeibaanwijzingen van Java naar Het Kanaal. Als Litkomsten Wetenschap 

 en Ervaring Aangaande Winden on Zeestroomingen in Sommige Gedeetten Van Den Oceaau 

 Uitgegenen Door Meet Koninklijk Nederlandsch Meteorologische Institut. Utrecht, 1859. 



f The mean height of the barometer for England generally is 29.94°. — Admiral FitzroJ^ 



856. The low austral barometer. — Captain Wilkes, U. S. N., and 

 Clarke Eoss, E.N., both, during theii* expeditions to the South 

 Seas in 1839-41, had occasion to_, remark upon the apparent defi- 

 ciency of atmosphere over the extra-tropical regions of the 

 southern hemisphere ; and the lovs^ barometer off Cape Horn had 

 attracted the attention of navigators at an early day. I observed 

 it in 1831 when doubling the Cape as master of the U.S.S. " Fal- 

 mouth," and wrote a paper on it, which was published in the 

 American Journal of Science in 1833-4. The more abundant 

 materials which the abstract logs since placed within my reach 

 have enabled me to go more fully into this subject than it was 

 possible to do while I was cruising in the Pacific more than a 

 quarter of a century ago. To ascertain whether these " barometric 

 anomalies,^* as they are called, are peculiar to the regions about 

 Cape Horn, ^or whether they are common to high southern 

 latitudes in all longitudes, the observations about Cape Horn 

 were aiTanged in one group ; those between 20° W. and 140° E. 



