160 



CLIMATE. 



strata of air, they deposit moisture upon it, because it is rela- 

 tively cold, having in fact the temperature of a higher region." 



A curious though common illustration of this theory has oc- 

 curred to me while traversing the north-western part of York- 

 shire, where I have seen a shower fall at the same moment on a 

 mountain and on the lower ground round it. On the former it 

 fell as small hail ; on the latter it was rain ; the drop started as 

 ice, and before reaching the lower ground was melted having, 

 no doubt, increased in weight during the fusion. I believe that 

 a considerable proportion of our ordinary rain commences its 

 descent in a frozen state ; that snow is often the parent of rain ; 

 and that hail is not congealed rain more frequently than rain 

 is melted hail. 



Such experiments as these on York Minster have been made 

 in many other situations, seldom so free from objection. The 

 results are generally of the same kind, but often the effect of 

 eddy winds is so great as to complicate and exaggerate the effect. 

 All buildings are in some degree objectionable as supports for 

 rain-gauges, for they generate strong deflections of the air. 



Desirous of knowing how far we could obtain sensible results 

 at much smaller elevations free from buildings, I tried, some years 

 ago, many experiments in my garden with five gauges placed at 

 1, 3, 6, 12, and 24 French feet above the surface. The results 

 obtained in parts of two years, viz. January 9 to October 14, 

 1843, and January 1 to September 2, 1844, which were read 

 off for me by Mr. Cooke, are appended. 



