oi 



by light; for, although the test-paper was screened from the sun, it was 

 exposed to diffused day-light, which, of course, is of longest duration in 

 June. Some authorities recommend the papers to be kept in the dark 

 during exposure. Ozone was observed to be most abundant during damp 

 and windy weather, and least so, when the atmosphere was comparatively 

 dry and calm. A south or S.W. wind always coloured the test-paper 

 most deeply; and a polar current, or one from the N.E., seldom gave 

 indication of the presence of much ozone. This may be one reason, I 

 do not say the sole one, why Easterly winds are unhealthy ; for ozone 

 undoubtedly possesses great disinfecting properties ; it is regarded by 

 many as Nature's own disinfectant. 



I may just contrast for a moment the small amount of ozone 

 registered at Cockermouth, with the abundance of the same agent at 

 Silloth, where it is present in such quantity that it has been found 

 necessary to make an alteration in the scale for that place. The test- 

 papers were so frequently coloured of a deeper tint than any on the 

 scale, that the Rev. F. Redford has had it extended up to twenty, 

 in place of ten. I believe that Silloth stands the highest of any known 

 place in the kingdom as regards ozone. 



Cloud. 



The amount of Cloud is estimated like ozone ; the scale being from 

 o when the sky is perfectly clear, up to lo when it is entirely covered 

 with cloud. The mean amount during the year was estimated at 62 ; 

 this is probably a little too low, since at Greenwich the mean is 67. 



The West coast of Scotland has also a similar mean ; whilst in the 

 interior, and on the east Coast of Scotland, the mean is only 6-o 

 according to Buchan's Meteorology. The smallest average amount of 

 cloud was in the months of July and April, and the greatest in 

 December and January. 



Humidity. 



The existence of cloud indicates a certain amount of moisture in 

 the atmosphere. The degree of humidity is calculated from the 

 difference between the readings of the dry and wet-bulb thermometers, 



