44 
observations, but the mean of the mean annual temperatures 
of York, Manchester, and Derby is about 48f 0 ; and hence 
the temperature of the springs rising at a low level corres- 
ponds very closely with the mean annual temperature of the 
air at a similar level. 
On ascending from the valleys to the upper parts of the 
higher hills, at elevations varying from about 1,000 to 1,300 
feet, the general mean temperature of the springs varies from 
45 J° to 45f°, being on an average about 45 J°. We may there- 
fore, I think, conclude that the mean annual temperature on 
the higher hills is 3° or 3J° less than in the valleys. This 
difference appears more striking when we reflect that, 
according to Dove's treatise " On the Distribution of Heat 
over the Surface of the Globe/' to arrive at the same low annual 
temperature as occurs on the hills, we must proceed somewhat 
farther north than the Orkney Islands. It may also be 
concluded that, on rising from the valleys to the tops of the 
hills, there is a diminution of about J° in the mean annual 
temperature for each 100 feet of elevation. This, however, 
does not invariably hold good, for the shelter of the hills 
compensates so much for the greater elevation, that the 
temperature in the lower parts of the more elevated valleys 
west of Sheffield is much the same as that of the more open 
country, at a level of fully 200 feet lower, as is also well 
shown by the manner in which the snow often lies in winter. 
Many springs in the neighbourhood of Sheffield are strong 
chalybeates. Several of the more remarkable were described 
upwards of a hundred years ago, in the very complete work 
by Dr. Short, of Sheffield, " On the History of the Mineral 
Waters of Derbyshire, Lincolnshire, and Yorkshire." As a 
general rule, there is only a small variation between the 
summer and winter temperature of chalybeate springs, which 
clearly points to their deep-seated origin ; and we may, per- 
haps, consider that this conclusion is still further established 
