DIRECTION AND VELOCITY OF THE WIND. 



211 



the ground^ but was removed^ in August 1858^ to a station 

 at the top of the tower of the Observatory, at an elevation 

 of no feet, where it has since remained. The results de- 

 rived from its indications are given in the annual volumes 

 of the ' RadclifiPe Observations/ in three tables, numbered 

 XII., XIII., and XIV. Table XII. shows the " Mean 

 Monthly Directions of the Wind every Two Hours /^ 

 Table XIII. the " Mean Bi-horary Velocities of the Wind 

 for each Month, estimated in the Directions given in Table 

 XII •;' and Table XIV. the '' Actual Mean Monthly Bi- 

 horary Velocities.'^ Up to the end of 1858 the mean 

 monthly directions were determined without regarding 

 the velocities j but in reducing the observations of 1859, 

 the present director, the Rev. Robt. Main, F.R.S., took 

 account of the velocities in determining the mean direc- 

 tions, and this method has been used through the succeed- 

 ing years ; and, as it is undoubtedly more correct than 

 that employed by the late Mr. Johnson, I have omitted 

 from my discussion the results obtained in the years 1856- 

 58. The following Table I. contains the mean bi-horary 

 directions of the wind, extracted from Table XII. of the 

 annual volumes of the ' Radcliffe Observations / and Table 

 II. contains the corresponding mean velocities in miles, 

 taken from Table XIII. 



Table I. 





oh. 



2h. 



4h. 



6h. 



8h. 



loh. 



i2h. I4h.'i6h, 



18 h. 



20 b. 



22 h. 





















































1859 



241 



244 



237 



231 



231 



226 



230 



231 



225 



232 



232 



235 



i860 



249 



254 



252 



253 



249 



250 



252 



247 



247 



250 



245 



257 



I86I 



234 



230 



227 



233 



224 



228 



232 



232 



232 



230 



231 



240 



1862 



234 



235 



234 



232 



227 



231 



228 



229 229 



235 



229 



233 



1863 



•225 



226 



229 



222 



226 



218 



218 



217 213 



214 



219 



219 



1864 



206 



211 



208 



200 



189 



187 



189 



196 



202 



198 



206 



201 



1865 



198 



204 



195 



193 



187 



188 



190 



196 



194 



200 202 



198 



