Various conjectures have been formed by natural philosophers, to account for the origin of rain : it appears, however, to be universally allowed, that such phenomenon is produced from the moisture or water which is absorbed from the surface of the globe by the heat of the sun, and conveyed into the atmosphere, whence it is again precipitated upon the earth; though the specific cause is by no means clearly determined.—According to chemical principles, the air itself is a solvent of water, and thus contributes to the formation of rain in the clouds, when they are saturated with aqueous humours. Now, as soon as two such volumes of condensed vapour meet each other in the atmosphere, in different temperatures, the necessary consequence will be precipitation ; in a manner similar to that from the vaulted ceiling or window of a cold room, when first heated.
Rain irrigates and softens the earth, thus adapting it to the nourishment of plants.—By falling on lofty mountains, and other elevated situations, this meteor carries down numerous loose particles of earth into the contiguous vallies, which are thereby not only ameliorated, or rendered more fertile; but the air is also purified from noxious exhalations, which are returned to the ground whence they were absorbed ; a natural process that remarkably contributes to enrich the soil. Lastly, it moderates the temperature of the air, and affords a supply of water to foun-tains, brooks, rivers, etc.
But, though gentle showers be in many respects beneficial to mankind, yet vehement rains coming down in torrents occasion great injury ; as they are often attended with violent inundations, which wash or carry off the finer particles into rivers, and thus impoverish the land. To remedy, in some degree, this inconvenience, it has been recommended to plant along their banks, orchards, or groves of trees, that produce esculent fruit for, according to practical observers; such trees beer greater abundance in wet, than in dry seasons. As. however, all kinds of grain are liable to be materially damaged by storms of rain, especially after being cut, some agriculturists have advised the erection of barn's at convenient distances, on large farms ; where corn, etc. may be speedily housed, preserved, and! much time, as well as labour, saved in the carriage : but, as these buildings would be exposed to the depredat ons of dishonest persons, it has farther been recommended to build,contiguously to such barns, cottages, to be inhabited by the labourers employed on the farm ; by which expedient the grain will be effectually secured, both from the injuries of the weather, and from the attacks of midnight plunderers.