TOL. XVII.] PHIX-OSOPHICAL TRANSACTIONS. 429 



vapours being taken away ; which, as they are variously compounded, and 

 brought by the winds, seem to be the causes of those various seasons which we 

 now find. In this case the region of air, every where at the same height, 

 would be equally replenished with the proportion of water it could contain, 

 regard being only to be had to the different degree of warmth, from the near- 

 ness or distance of the sun ; and an eternal east wind would blow all round the 

 globe, inclining only to the same side of the east, as the latitude does from the 

 equator ; as is observed in the ocean between the tropics. 



Next, let us suppose this ocean interspersed with wide and spacious tracts of 

 land, with high ridges of mountains, as the Pyrenean, the Alps, the Apennine, 

 the Carpathian in Europe, Taurus, Caucasus, Imaus, and several others in 

 Asia ; Atlas and the Montes Lunae, with other unknown ridges in Africa, 

 whence come the Nile, the Niger, and the Zaire ; and in America the Andes, 

 and the Apalatean mountains, each of which far surpass the usual height to 

 which the aqueous vapours of themselves ascend, and on the tops of which the 

 air is so cold and rarefied, as to retain but a small part of those vapours brought 

 thither by the winds. Those vapours therefore that are raised copiously in the 

 sea, and by the winds carried over the low lands to those ridges of mountains, 

 are there compelled by the stream of the air to mount up with it to the tops of 

 the mountains, where the water presently precipitates, gleeting down by the 

 crevices of the stone, and part of the vapour entering into the caverns of the 

 hills, they are collected, as in an alembic, into the basins of stone they find 

 there, which being once filled, all the overplus of water that comes thither runs 

 over by the lowest place, and breaking out by the sides of the hills forms single 

 springs ; many of these running down by the valleys or guts between the ridges 

 of hills, and coming to unite, form little rivulets or brooks ; many of these 

 again meeting in one common valley, and gaining the plains, being grown less 

 rapid, they become a river ; and many of these being united in one common 

 channel, make such streams as the Rhine, the Rhone, and the Danube; which 

 latter one would hardly think the collection of water condensed out of vapour, 

 unless we consider how vast a tract of ground that river drains, and that it is 

 the aggregate of all those springs which break out on the south side of the 

 Carpathian mountains, and on the north side of the immense ridge of the Alps, 

 which is one continued chain of mountains from Switzerland to the Black Sea. 

 And it may generally pass for a rule, that the magnitude of a river, or the quan- 

 tity of water it discharges, is proportionable to the length and height of the 

 ridges, from whence its fountains arise. 



Thus then is one part of the vapours, blown upon the land, returned by the 

 rivers into the sea, from whence they came. Another part, by the cool of the 



