EF. Loomis— Observations of the U. 8. Signal Service. 17 
In twelve of the cases the stations which show the lowest pres- 
sure are the same as reported above for the north winds, but in 
six of the cases the lowest pressure was farther to the west. 
The average direction of the low center from Mount Washing- 
ton was nearly at right angles to the direction of the winds. 
In all of these cases (except Nos. 28 and 29) the pressure was 
above thirty inches on the west side of Mount Washington 
and generally at a distance of about five hundred miles, but in 
a majority of the cases the center of high pressure was south- 
west of Mount Washington. 
With a west wind of eighty miles per hour, the low center 
was generally near some one of the stations already named. 
In six of the cases the low center was near one of the stations 
the station reporting the least pressure ranges from about zero 
to somewhat over 90°. On account of the small number of 
stations, it is generally impossible to assign exactly the position 
of the center of least pressure, but apparently the angle which 
the wind’s direction made with the direction of the low center 
was in some cases less than 45°. In all of these cases (except 
Nos. 45 and 47) the pressure was above thirty inches on the 
west side of Mount Washington and generally at a distance of 
about eight hundred miles; but in all cases the center of high 
pressure was somewhat south of west from Mount Washington. 
With a southwest wind of sixty-five miles per hour, the 
direction of the station reporting the lowest pressure ranges 
from N..25° E. to S. 75° W., the average direction of the low: 
center making an angle of about 90° with the direction of the 
wind. In the case of No. 58 there was a low center in Vir- 
remaining ten cases its direction was almost exactly west, and 
its distance about 1,300 miles. 
ith a south wind of sixty miles per hour on Mount 
Washington the low center is generally found nearly west from 
that station. The exceptions are Nos. 71, 75, 77 and 78. In 
the case of seventy-one we find the pressure at Montreal was 
less than at Burlington, so that it appears possible that at. the 
height of 6,000 feet the center of least pressure was not over 
Portland but northwest of Montreal. In the case of seventy- 
five the pressure at Ottawa was only -07 inch greater than at 
Am. Jour. ee Serres, Vou. XVI, No. 97.—Jan., 1879. 
