THE FARMER AT HOME. 197 



and renders the soil fertile ; snow covers and preserves the tender 

 vegetables from being destroyed by too severe a frost. But hail does 

 none of these. In winter it lies not sufficiently close to cover vege- 

 tables from the nipping frosts ; and in spring and summer it not only 

 has a chilling and blasting effect, but often does great damage to the 

 more tender plants by the weight of the stones. In great hail storms 

 the damage done in this manner is prodigious. 



Hail is one of the natural phenomena for which it is difficult to 

 account in any satisfactory manner. It is certain that, on the tops of 

 mountains, hailstones, as well as drops of rain, are very small, and 

 continually increase in bulk, till they reach the lower grounds. It 

 would seem, therefore, that during their passage through the air they 

 attract the congealed vapor, which increases them in size. But here we 

 are at a loss how they come to be solid hard bodies, and not always soft, 

 and composed of many small stars like snow. The flakes of snow, no 

 doubt, increase in size as they descend, as well as the drops of rain 

 or hailstones ; but why should the one be in soft crystals, and the other 

 in large hard lumps, seeing both are produced from congealed vapor ? 



Some modern philosophers ascribe the formation of hail to 

 electricity. Signor Beccaria supposes hail to be formed in the 

 higher regions of the air, where the cold is intense, and where the 

 electric matter is very copious. In these circumstances, a great 

 number of particles of water are brought near together, where they 

 are frozen, and in their descent collect other particles, so that the 

 density of the substance of the hailstone grows less and. less from the 

 centre ; this being formed first in the higher regions, and the surface 

 being collected in the lower, drops of rain and hail agree in this, that 

 the more intense the electricity that forms them, the larger they are. 

 Motion is known to promote freezing, and so the rapid motion of the 

 electrified clouds may produce that effect. A more intense electricity 

 also, he thinks, unites the particles of hail more closely than the more 

 moderate electricity does those of snow. In like manner we see 

 thunder clouds more dense than those that merely bring rain ; and 

 the drops of rain are longer in proportion, though they fall not from so 

 great a height. 



HAIR. This is a fine, threadlike, more or less elastic, substance, 

 of various color, and constitutes the covering of the skin, particularly 

 of the class of mammalia. The same variety and brilliancy are dis- 

 played in the feathers of birds, which may be considered as analagous 

 to hair, of the most variegated and beautiful colors. In quadrupeds, 

 it is of the most various conformation, from the finest wool to the 

 quills of the porcupine, or the bristles of the hog. The hair, which 

 is spread over almost the whole of the skin, is comparatively short 

 and soft. On particular parts, a longer, thicker, and stronger kind is 

 found ; as, for instance, the mane and tail of the horse, the lion's 

 mane, the covering of man's occiput his beard, and the beard of goats. 



