288 



REPORT ON THE METEOROLOGICAL OBSERVATIONS 



being only 2 miles per hour ; the sky all but clear, only one-fifth 

 being covered with clouds ; and an average of nine hour's sunshine 

 a day. The means of the observations of the daily maximum were 

 43°'0 at Gallowhill and 41 0< 6 at Winterlaw. The heights of the 

 trees surrounding the instruments at Winterlaw, taken in connec- 

 tion with the greater obliquity of the sun's rays in October, are 

 probably sufficient to account for the difference. An examination 

 of the Avhole observations at both stations at this season shews that 

 the point requires further observation for its elucidation; the ques- 

 tion being greatly complicated by the fluctuations of temperature 

 which repeatedly occur in connection with the frequent autumnal 

 storms at this season. 



Results of the Dry and Wet Bulb Hygrometer. — The results of 

 the dry-bulbs, giving the temperature of the air, shew that at 9 p.m. 

 the temperature at both stations is very nearly the same during all 

 the months, the difference in no month exceeding two-tenths of a 

 degree, thus shewing a remarkable agreement with the results of the 

 minimum thermometers at both stations. 



Equally remarkable is the agreement of the results of the 9 a.m. 

 observations of the dry-bulb thermometer with those of the maxi- 

 mum thermometers at both stations. Comparing the two results, as 

 those of the maximum temperatures were compared, we obtain this 

 result : — 



Combining the two sets of results, it is seen that during 1873- 

 74 the mean temperatures at 9 p.m. inside and outside the wood, at 

 Carnwath, were practically the same, and remained so, at least, till 

 the time of occurrence of the minimum fur the night; that in the 

 spring and early summer months, by 9 a.m. the mean tempera- 

 ture inside the wood had risen higher than that outside, and con- 

 tinued to rise still further above it till the time of occurrence of the 

 daily maximum; and that in autumn, by 9 a.m. the mean tempera- 

 ture inside the wood was lower than that outside, and continued 

 lower till, at least, the time of the daily maximum. 



