138 



REPORT 1855. 



Table YI. — Mean hourly horizontal motion of the air in miles for each month. 

 See Plate X. fig. 3. 



Winter. 

 Dec, Jan., Feb. 



Spring. 

 Mar., Apr., May. 



Summer. 

 June, July, Aug. 



— V — 



Autumn. 

 Sept., Oct., Nov, 



15-6 miles per hour. 121 miles per hour. 11-8 miles per hour. 11-5 miles per hour. 



T.4BLE YII. — Horizontal motion of the air for the years 1852, 1853, 1854, 



and 1855. 



* Leap year. 

 The sums of all the changes in the direction of the wnd are in the following order : — 



{28 revolutions in 1852. n2 revolutions in 1852. 



24 revolutions in 1853. „ w = i- ^ J ^2 revolutions in 1853. 



26 revolutions in 1854. n-w.s.e.n. < ^ ^^^^X\^'i^ox,% in 1854. 



24 revolutions in 1855. \\^ revolutions in 1855. 



The excess of the direct over the retrograde motion was therefore — 

 in 1852, Sixteen revolutions, 

 in 1853, Twelve revolutions, 

 in 1854, Twenty-four revolutions, 

 in 1855, Fourteen revolutions. 



Table V. gives the hourly amount of rain, and is illustrated in fig. 1, 

 Plate X. As far as four years are capable of indicating, it would appear 

 that the minimum amount of rain falls during the first three hours after 

 midnight, and that there are three periods in the day wlien an increased 

 amount of rain falls, namely, between seven and eight o'clock in the morning, 

 between one and two in the middle of the day, and between eight and nine 

 in the evening; but before any satisfactory conclusions can be arrived at on 

 this subject, it will be necessary to obtain averages for a longer period. 



Table VI. gives the average hourly motion of the air in miles for each 

 month, direction not being regarded. The curves shown in fig. S, Plate X., 

 exhibit the comparative results given in this table, by which it appears that 

 the greatest amount of motion in the air taices place in the months of Decem- 



