422 TRANSACTIONS OF SECTION A. 
Calculations of the gradient wind at 7 a.m. and 6 p.M., as given by the distri- 
bution of the isobars on the M.O. charts, were made, and compared with the 
winds recorded in ascents within two hours of these times. 
The ground wind velocity is generally below that given by the formula, but 
becomes equal to it at about 650 m. 
The height at which the observed wind reaches the theoretical velocity varies 
considerably with the direction of the wind, and with the season. 
At the ground the observed wind has a component directed towards the low 
pressure, the angle to the theoretical averaging 22°, This decreases with height 
until at 2,500 m. the average angle is only 8°. 
Diagrams and tables substantiating the above conclusions appeared in detail 
in the paper, which included also a number of subsidiary questions. 
Note.—1 metre per second = 2°24 miles per hour, 
4. Report on the Investigation of the Upper Atmosphere. 
See Reports, p. 105. ; 
5. On the Temperature of the Upper Atmosphere. 
By Miss Marcarer Wuirtes, M.Sc. 
Conclusions are based on the results of kite and captive balloon ascents, made 
daily at Glossop Moor, Derbyshire, during 1908 and 1909, and comprising some 
thousand ascents. 
Temperatures are measured in degrees Centigrade, heights in metres above 
m.s.l., and temperature gradients in degrees C. per 100 metres; a decrease of 
temperature with height being reckoned a positive gradient. 
Variation of Temperature with Height.—The average temperatures at suc- 
cessive 250 m. above m.s.l. were as below :— 
| . 
— | Ground | 559 | 750 | 1000 | 1250 | 1500 | 1750 | 2000 
335m. 
Temperature °C. 9:0 76 59 4:2 30 2°0 1-2 0-4 
These figures agree closely with those for other English stations. 
The average temperature gradients, calculated from the individual gradients, 
are :— 
Ground | 500 750 | 1000 | 1250 | 1500 | 1750 | 
| a to 500 to 750 | to 1000 | to 1250 to 1500 | 01750 to 2000 | 
| Temperature | | 
Gradient 085 | 075 | 062 | Ol | 048 | 042 | O43 | 
Lemperatures and Temperature Gradients under Cyclonic and Anticyclonic 
Conditions.—At all levels, day or night, summer or winter, the temperature is 
lower, and the rate of fall of temperature with height more rapid, under cyclonic 
than anticyclonic conditions. The average values of temperature and tempera- 
ture gradient are as follows :— 
Average Temperatures. 
—— Ground | 500 | 750 | 1000 | 1250 | 1500 | 1750 | 2000 
68 | 
” 
Summer, A... 13°4 114 9°6 81 58 5:1 3°9 
a5 OSs au 115 9°8 76 57 4] 30 18 14 
Winter, A... 3°8 2°8 15 02 |—0°5 |—1'8 |\—2°5 |—3°3 
Cot : 39 2-7 11 —06 36 (—44 —57 
2 al ES Fe 
