Phil. Mag. S. ft Vol. 37. PI. IX. 



jq* 36™ 37" 7 38™ 39 m 40 m 



Wind velocities observed at Smithsonian Institution, February 20, 1893, 

 with a Robinson anemometer (aluminum cups) registering every 

 five revolutions. 



Abscissae = Time. 



Ordinates = Wind velocities in miles per hour. 



