United States Weather Maps. 3 
arrows show the direction at the corresponding points as inter- 
polated from the first four numbers. The lengths of the arrows 
are proportioned to the velocity of.the different win 
From these diagrams it will be apparent that in each quad- 
rant the direction of the wind for high barometer is nearly op- 
posite to the direction in the same quadrant for low pometie 
the differences in the several quadrants being as follo 
West quadrant. South quadrant. East quadrant. North Adie 
4 Ses 4° 9! ° 
For high barometer the average angle which the winds make 
with radii drawn from the point of greatest pressure is 42° 18'; 
for low barometer the average angle which the winds make with 
radii drawn from the point of least pressure is 43° 1’. In each 
case, therefore, the wind’s direction is almost exactly midway 
between tangential ae : radial movement, but approaching 
somewhat nearer to the 
In order to determine i what height above the level of the 
sea the law of movement shown in the pee Haig 22 
vails, I discussed the observations made on the mit of 
Washington at an elevation of 6,285 feet above the level of oH 
Sea, in the same manner as [ had already discussed the observa- 
tions at the other stations, and obtained the following results: 
For Ne barometer on Mt. Washington. 
: est quadrant. | South quadrant. | East quadrant, , North quadrant. 
Velocity of wind, ae miles. 44 miles 37 miles 32 miles. 
Direction of wawie N. 55° 77 W.| N. 76° 35’ W.| 8. 53° 44” ‘W.| N. 20° 6” E. 
Height of baromete 
reduc, to sea- aoe, 29°54 29°60 29°76 29°76 
For high barometer on Mt. Washington. 
West quadrant. | South quadrant.; East quadrant. em or Oe 
——- of wind, 32 miles. 18 miles. 38 miles. 32 
Direction of wind, | §. 14° 377 B.|N. 4° 8’ W.|N. 54° 48’ W.| N. 57° 52” W. 
Height of barometer 
c. to sea-level, 30°28 30°21 30°03 30°11 
These a are graphically represented by the sg aig dia- 
grams, Nos. 3 and 4, in which, for convenience, the force of the 
wind is represented upon a scale only one-fourth as ae as in 
the two previous diagrams. 
The number of observations from which the results in Nos. 
3 and 4 are agen is much less than for Nos. 1 and 2, and this 
will Signed explain some anomalies which might be ex- 
pecte a isappear in the average of a greater number of ob- 
Servatio 
A ial comparison of these diagrams will show that the 
Winds represented in Nos. 8 and 4 correspond pretty well va 
what might be expected from the winds represented in Nos. 1 
