ON THE SEASONAL VARIATIONS OF TEMPERATURE. 



483 



somewhat modified if the observations had been extended over the whole 

 year instead of nine months, but not, I think, to any great extent, there 

 being an obvious reason why the temperature of the estuary should be 

 higher than that of the river as compared with that of the air, viz., the 

 fact that when the tide rises it passes over the extensive tracts of sand 

 which in the Solway Firth are left bare by the receding tide, and in 

 sunny days become heated by the sun. 



By the kindness of Mr. Beck and Mr. Lindsay, observations were 

 made from August 8 to 19, and from September 13 to October 1, on 

 Lochrutton loch, with the following results : — 



From this we may probably infer that during at least the autumn 

 and winter months, and possibly in summer also, the temperature of the 

 loch is, as a rule, in excess of that of the air. But the observations ave 

 too limited in number to warrant any decided conclusion being founded 

 upon them. 



Observations of Temperature of Rivers NitJi (DumfriessJiire') and Bee 

 (Kirkcudbrightshire) for year 1890-91. 



The observations of the temperature of the Nith at Dumfries were 

 begun on September 8, 1890, and continued to August 31, 1891. They 



Curve VI.— Dee at Tongland, Kirkcudbrightshire. 12.30 p.m. 

 Jit iM'oaiy ______ 



were taken daily, with some exceptions, at or near noon. Those for the 

 Dee were taken at Tongland by Rev. WiUiam I. Gordon, for the most 

 part alsa daily, about 12.30 p.m. The following table shows the monthly 

 means both for air and water during that period at each station : — 



I I 2 



