70 
thrown over them a fleecy mantle, which serves as a defence against the 
piercing cold, snow being a bad conductor of heat. For the earth has always 
produced from the jar of its elements an internal heat, whose temperature at 
a sufficient depth is found to be equal to 48 of Fahrenheit’s thermometer. 
Hence a continual contest between the heat of the earth and the snow, 
the result of which is carrying the temperature to the intermediate point 
between this and the freezing point. 
The object, however, of the present section is to prove that ice, or what 
is the same, enow , has its fertilizing power from its possessing a super¬ 
abundance of oxygen , which it imparts to the earth. 
Dr. Grew, in his discourse on the nature of snow observes, “ that many 
parts thereof are of a regular figure, for the most part, being, as it were, so 
many little stars of perfect ice; upon each of which are set other collateral 
points at the same angles, as the main points themselves; among these are 
divers other irregular, which are chiefly broken points or fragments of the 
regular ones; others also by various winds, seem to have been thawed, and 
frozen again into irregular clusters, so that it seems as if the whole body of 
snow was one entire mass of icicles irregularly figured; that is, a cloud of 
vapours being gathered into drops, the said drops do forthwith descend; and 
in their descent meeting with a freezing air, as they pass through a cold 
region, each drop is immediately frozen into an icicle, shooting itself into 
several points; but still continuing to descend, and meeting with some inter¬ 
mitting gales of warmer air, or by their being continually wafted to and fro, 
touching upon one another, some are a little thawed, blunted, and again 
frozen into clusters, or entangled, so as to fall into what we call flakes, 
although in reality snow is firm ice, and the lightness of it is owing only to 
the excess of its suiface, m comparison to the contained matter, as a guinea 
can be so extended in surface as to ride upon the smallest breath of air.” 
And all so forming an harmonious whole, 
Shade unperceiv’d, so softening into shade; 
That as they still succeed, they ravish still. 
But wandering oft, with rude inconscious gaze, 
Man maiks not thee, marks not the mighty hand 
That, ever busy, wheels the silent spheres; 
Works in the secret deep; shoots, streaming, thence 
The fair profusion that o’erspreads the spring; 
Flings from the sun direct the flaming day; 
Feeds ev’ry creature; hurls the tempest forth, 
And, as on earth this grateful change revolves, 
With transport touches all the springs of life. 
Thomson. 
