TRANSACTIONS OP THE SECTIONS. 29 



land, and is to a great extent condensed ; and to its condensation we are to look for 

 the great differences of winter climate in the same latitudes of the northern hemi- 

 sphere. 



The steam in the tropical regions of the Pacific Ocean that flows towards the 

 north-east, with the south and south-west winds that prevail in those parts, is car- 

 ried to the American ridge, and is there condensed. The result is, that the south- 

 west side of this chain of mountains is wet and warm in the winter, from the tropics 

 to Nootka Sound, and still further north. Captain Cook, Lewis and Clarke, Cap- 

 tain B. Hall, and Humboldt, describe the climate of this part in such terms as can 

 leave no doubt of the fact. But beyond this ridge to the north-east we have a 

 different climate in the winter, one as remarkably cold and dry as that on the other 

 side is wet and warm. Captain Parry, Captain Back, and Lewis and Clarke, re- 

 present the country in the winter from the shores of the Frozen Sea to the Missouri 

 as very cold and generally dry. Here we trace the effects of the condensation of 

 steam, and of its absence, on the climates of these parts. 



In the Old world the same causes produce the same effects. On the south-west 

 sides of the various ridges of mountains, the weather is in the autumn and early 

 part of winter very wet and warm for the latitudes. This is particularly seen in 

 Hindoostan and the south-west coast of Italy, while to the north-east of these 

 mountains the climate is cold and dry, over Poland, Russia, Central Asia, and 

 Siberia. 



The very heavy rains which fall to the south of the Himalaya Mountains indicate 

 the great condensation of steam that takes place in that part of the world ; and the 

 effect produced on the climate is remarkable. The valleys are habitable to a great 

 elevation ; and Major Archer states that wheat is grown at a height of 13,000 feet 

 in latitude 32° north, whilst Humboldt represents 1300 feet as the greatest height 

 at which wheat can be grown in Teneriffe, a place four degrees more south. But 

 when the steam that is in the atmosphere is all, or nearly all, condensed against the 

 sides of elevated ridges, it is evident that it cannot carry its warming influence 

 further north. Hence the part of the globe between these ridges and the polar 

 regions will, in the autumn and winter, be dry and very cold. 



In continuation, the author illustrated his views by supposing cases of great 

 changes of the elevation of land and the distribution of land and water on the globe. 



From the whole inquiry he concludes, that the relative situations of land and 

 water are not the cause of the great differences of climate in corresponding latitudes ; 

 but that the great differences in the winter climates of certain parts of the northern 

 hemisphere are attributable to elevations of land intercepting and condensing atmo- 

 spheric steam, and thus rendering certain parts wet and warm, while cutting off the 

 supply from more northern parts leaves them dry and cold. 



On the Temperature of the Air in York Minster. By John Phillips, 



F.R.^.f Gr.iS. 



It may be remarked, that the vastness and loftiness of the interior of York Minster 

 render the air within it, in a great degree, free from violent local draughts, and yet 

 subject to a continual gentle circulation. At the time when the observations now to 

 be noticed were made, there was no heating apparatus in the church : the lights used 

 were a few scattered tapers. The observations were made in the interval from April 

 8, 1808, to July 31, 1811. There is an interruption from April 27 to May 21, 1810, 

 owing to the absence of the observer, and a few single days are left without observa- 

 tion. From April 8, 1808, to July 12, 1808 (inclusive), the hour of observation is not 

 given. Afterwards it is given for each day, the hours varying from 11 to 5 ; the far 

 greater number are taken at about 1, and a sufficient proportion about 2 and 3, to render 

 the mean of the whole about 2 p.m., or nearly the epoch of maximum daily tempe- 

 rature in the open air. The observations are registered to half and one-fourth degrees, 

 and, as far as can be judged from inspection, appear to be very faithfully recorded. 

 The following are the deductions: — 1. The comparative mean annual temperature 

 within and without York Minster. 2. The comparative mean monthly temperature 

 of the interior of York Minster, and the mean monthly, and mean maximum monthly 

 temperature of the surrounding atmosphere. 3. The comparative epochs of mean 

 annual temperature for the same conditions. 



