XCVlll 



Genekal Results of the Makerstoun Observations. 



Table 93. — Number of Observation Hours in 24 at which (within 10™) the Wind blew with a force of 

 01 lb. or upwards, for each Month in the Years 1843-6. 



Year. 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Mean. 



1843 



18-0 



16-2 



11-6 



12-9 



15-3 



17-7 



14-7 



9-3 



10-2 



15-5 



12-4 



16-8 



14-2 



1844 



8-6 



12-3 



14-7 



14-3 



10-2 



16-0 



11-3 



16-1 



17-7 



170 



17-7 



6-8 



13-6 



1845 



14-4 



18-7 



20-3 



16-2 



20-7 



18-3 



17-8 



18-2 



15-8 



21.1 



15-2 



19-6 



18-0 



1846 



15-9 



16-8 



14-6 



17-2 



19-5 



15-7 



21-0 



17-8 



17-5 



18-8 



17-7 



17-7 



17-5 



Mean 



14-2 



160 



15-3 



15-1 



16-4 



16-9 



16-2 



15-3 



15-3 



18-1 



15-7 



15-2 



15-8 



203. Annual Variation of the Number of Observation Hours at which the Wind was observed to blow 

 with a force of 0-1 lb. or upwards. — Four years' observations are evidently insufficient to shew this annual 

 variation fi.*ee from irregularity. The wind blew during the greatest number of hours in October and in June, 

 and it blew during the least number of hours in January. See Table 93. 



Table 94. — Mean Pressure of the Wind while blowing, for each Month in the Years 1843-6. 



Year. 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Mean. 





lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



lb. 



1843 



1-66 



1-27 



0-65 



0-89 



0-62 



0-55 



0-56 



0-45 



0-38 



0-58 



0-92 



100 



0-79 



1844 



0-96 



0-73 



0-85 



0-69 



0-46 



075 



0-33 



0-56 



0-46 



0-80 



0-86 



0-33 



0-65 



1845 



0-76 



0-66 



0-95 



0-91 



0-77 



0-73 



0-53 



0-50 



0-43 



0-72 



0-80 



M9 



0-75 



1846 



0-70 



0-67 



0-99 



0-48 



0-67 



0-56 



0-56 



0-26 



0-25 



0-55 



0-63 



0-49 



0-57 



Mean 



1-02 



0-84 



0-86 



0-74 



0-65 



0-65 



050 



0-44 



0-38 



0-66 



0-80 



0-75 



0-69 



204. Annual Variation of the Mean Pressure of the Wind tvhile blowing. — We have in No. 199 consi- 

 dered the annual variation of the mean pressure of the wind with reference to time, the sums of the observed 

 pressures being divided by the whole number of observations ; in the present case the sums of the observed 

 pressures are divided only by the number of observations for which the wind was blowing : thus, in November 

 1843, the wind was observed blowing at little more than half the whole number of observation hours ; conse- 

 quently the mean pressure with reference to the whole number of observations for that month (Table 90) is 

 only a half of the mean pressure with which the wind was observed blowing (Table 94). The law is the 

 same for both means, but it is better marked in the present case than in that of No, 199. The wind blows with 

 the greatest force in January, and luith the least force in September. 



205. Diurnal Variation of the Number of Observation Hours at which the Wind was observed blowing. 

 — The following are the mean numbers of times, at which the wind was observed blowing 0*1 lb. or upwards, 

 in the four years 1843-6 : — 





l?"! IhA.M. 2'» Z^ i^ 5^ 6t> 7^ 8^ 9^ iCi llli 0^ l^ p.m. 

 150 156 155 164 162 163 176 190 214 224 242 251 262 266 



2li 3l> ih 5^ eb 7^ 8^ 9l> 10'» Jl*" 

 266 258 249 240 225 211 186 169 162 160 



The wind blew most frequently at l'^ 40™ p.m., the epoch of maximum temperature ; it blew seldomest about 

 l*- A.M. 



206. Diurnal Variation of the Mean Pressure of the Wind while bloiving (see No. 204). The following 

 are the means for each hour, as deduced from the observations for the four years 1843-6 : — 



121i I'l A.M. 2^ 3li 4'' 5"^ 6^ 7^ S^ 9^ iCi ll^ 0'» l^ P.M. 2h Z^ i^ 5^ 6^ 7^ 8^ 9^ lOi 11»> 



lb. lb. lb. lb. lb. lb, lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb. lb, 



0'67 0-67 0-65 0-69 0-70 0-71 0-67 0-64 0-70 077 0-78 0-80 078 0-80 0-80 0-75 070 067 0-61 0-58 0-61 0-65 0-67 0-69 



