376 Dr. Thomson on the ("Nov, 



Article VIII. 



On the Annual Fall of Rain at Glasgow. 

 By Thomas Thomson, M.D. F.R.S. 



It is a general opinion that the quantity of rain which fails at 

 Glasgow is greater than the fall at Edinburgh ; but this opinion 

 does not seem founded upon any well-authenticated documents. 

 It is probable that it rains more frequently at Glasgow than at 

 Edinburgh ; at least this is the general opinion, and is not 

 denied by the inhabitants of Glasgow themselves. But to judge 

 from the registers kept at Glasgow and near Edinburgh, the 

 quantity of rain which falls in the neighbourhood of the former 

 city is rather less than what falls in the neighbourhood of the 

 latter. We are in possession, indeed, of no regular table of the 

 weather at Edinburgh ; but a rain gauge has been long kept by 

 the Duke of Buccleugh at Dalkeith Palace, within six miles of 

 Edinburgh ; and the annual depth of rain which falls at this 

 place is regularly published. Now this is uniformly greater than 

 the fall of rain at Glasgow. Indeed when the situation of Glas- 

 gow is considered, one would expect less rain at it than at 

 Edinburgh. It is nearly 20 miles inland from the west coast ; 

 and is, therefore, beyond the immediate influence of the Atlantic, 

 which renders some parts of the north-west of England so 

 rainy ; while its distance from the east coast, and the high land 

 between it and Edinburgh, screen it from those violent rains 

 when the east wind blows, which are so common in Edinburgh. 

 The distance of the hills from Glasgow is further than from 

 Edinburgh ; and it is in some degree screened by high grounds 

 both on the east and the west. 



The city of Glasgow lies in north latitude 55° 51' 32", # and in 

 longitude 4° 16' west from Greenwich. The surface of the 

 Clyde at Glasgow at low water is probably elevated about 15 feet 

 above the surface of the sea at Greenock ; for the tide rises only 

 a few feet at the new bridge, and it proceeds but a very little 

 beyond Ruthergien bridge, which is scarcely the eastern boun- 

 dary of this populous city. The College gate is elevated 60 feet 

 above the Clyde ; and the Macfarlane observatory, situated in the 

 College garden, must be very nearly at the same elevation. A 

 rain guage, constructed by Crichton, was placed upon the top of 

 this observatory in the year 1801 ; and a regular register has 

 been kept of the rain ever since by the Professor of Astronomy. 

 This rain gauge is elevated about 20 feet above the surface of 

 the garden, or 80 feet above the Clyde. It is situated on a plain, 

 at some distance from any houses, and not overlooked by any 

 trees. The situation, therefore, with the exception of its height 

 above the river, is as favourable for accurate observations as can 

 be. It deserves to be mentioned that the rain guage at Dalkeith 



* Edinburgh is in north latitude 55° 56' 42". It is, therefore, 5' 10" further 

 north than Glasgow, which is very nearly six miles. 



