228 



tioned. From these we bave choosen the registered numbers 

 between 2'^ — 3'^ p. m. and, after having calculated Ihe velo- 

 city in ™/sec, the results are layed out in curves on the 

 plate with the title ..Variations in the velocitij of irinds". 

 On the figure the abscissa signifies time; every millimeter 

 15 seconds and every centimeter alsQ 2.5 minutes. 



On the ordinata every cm represents the velocity of 

 wind in 'Vsec. In the margin of the plate some observations 

 are given for every day viz the mean velocity and direc- 

 tion of wind, the barometer and the temperature, received 

 through the kindness of the Director Biese from the central 

 meteorological institution here. Afterwards when the cur- 

 ves were printed, it was found that the mean velocities had 

 to be corrected with a rather big quantity and as this velo- 

 city was greater than the mean velocity, calculated from our 

 observations, we fmd it best to give them all here anew: 



Ps "^ (=1 . The velocity 



« r? S S .£? 2 -J £ c ^ by 2li Om liy 31i Um 



^) On the plate there is a misprint EWE for ENE. The four 

 last curves, beginuing from the 23 Jauuary, are imfortimately put up- 

 side down in printing. The starting point is at 60 minutes and the 

 ordinates must be counted from above. For our present aim this in- 

 version has not done much damage, but -when reading it is best to 

 invert the plate itself and read it in this position. 



