2 E. Loomis — Contributions to Meteorology. 



From this chart we see, that north of the parallel of 30 

 degrees, storm tracks in all longitudes almost invariably pursue 

 an easterly course, but generally they show an inclination 

 toward the north of east ; while within the tropics, storrn tracks 

 almost invariably tend westerly, with an inclination toward 

 the north of west. We also notice that none of the storm 

 tracks reach down to the equator. The lowest latitude of any 

 centre of low pressure which has been distinctly traced is 6'1° 

 N., and there are eight cases of cyclonic storms whose paths 

 have been traced to points south of lat. 10° N. Hard gales 

 and violent squalls of wind sometimes occur directly under the 

 equator, accompanied by sudden oscillations of the barometer ; 

 but within six degrees of the equator, the depression of the 

 barometer has never been found sufficiently great, and the de- 

 pression has not been maintained with sufficient steadiness, to 

 enable us to identify an area of low pressure in its progress 

 from day to day. 



The tropical cyclones which have been found to pursue a 

 westerly course are limited to two districts. 1. The Atlantic 

 Ocean, and chiefly its western part near the West India 

 Islands; and 2. the region south of the continent of Asia. 

 Tropical cyclones have never been observed in any part of the 

 Pacific Ocean, with the exception of its western portion near 

 the continent of Asia and the neighboring islands. In my 

 fifth paper I gave a table showing the leading particulars 

 respecting the most violent cyclones originating near the West 

 India Islands, whose paths had been investigated previous to 

 1875; and in my fourteenth paper I gave a similar table based 

 on the observations contained in the International Bulletin. 

 The average course of the cyclones enumerated in nry fifth 

 paper, while they were moving westward, was 26 degrees north 

 of west; and the average course of those enumerated in my 

 fourteenth paper, during the same part of their course, was 26J 

 degrees north of west. 



According to Maury's Pilot charts of the North Atlantic, the 

 average direction of the wind for that part of the Atlantic 

 Ocean in which these cyclones most frequently occurred during 

 the three months, August, September and October (which 

 months include nearly all the cyclones referred to), is two de- 

 grees north of east. According to the charts of the United 

 States Hydrographic Office, which include all the observations 

 collected by Maury and also those collected by the British 

 Meteorological Office, the average direction of the wind is 4f 

 degrees north of east. The average course of West India 

 cyclones, while moving westward, differs therefore from 28 to 

 30 degrees from the average course of the wind. But if we 

 make a comparison of the winds immediately succeeding each 



