188 



SOUTH WINDS ARE THB DRIEST 



reo6vered ttemselve^ aa the day advanced and grew warmer, and 

 eventually they so completely regained their original position that 

 Mr. Eogers at first thought his gardener had Cut away all that drooped 

 and impeded the path the day before. In this case it is almost certain 

 that the drooping was caused by the expulsion of air and fiuid from the 

 tissue by the contraction caused by cold, and that the revival was 

 attributable to the reflux of air and fluid. 



I find, however, from Mr. Thompson's observations, that the 

 greatest dryness we experience in this climate is, not when the 

 wind is in the east, but when it is in the south. For example : 

 - in nine years, between 1836 and 1834, the four driest days 

 were in the year 1834, in June, when it was 33° on the 1st, 35° 

 on the 2nd, and 31° on the 21st; on the 1st of June, 1833, it 

 was 30°, and always with a south wind ; and, during the whole 

 of those nine years, there was but one other day on which the 

 dryness was found as high as 30°, namely, on the 10th of April, 

 1834, with a north-east wind. The duration of dryness, with a 

 south wind, was, however, very short, not exceeding one or at 

 most two days, and was invariably accompanied with great heat 

 and foUowed.by heavy rain, while the north-easters last for weeks, 

 without rain, and with a comparatively low temperature. The 

 following statement puts this in a clear light. There occurred 

 between 1886 and 1834, inclusive, — 



7 days, above 20° of dryness. 



These facts sufficiently explain the fatal effects of certain 

 winds upon vegetation, the small comparative value in this 

 country of walls with north and east aspects, and the general 

 want of success that attends late spring planting. Here, also, 

 we in part discover an explanation of the utility of shades 

 interposed between the sun and plants newly committed to the 

 earth : they not only cut off the solar rays, but also intercept 



