The fancy of the Greeks delighted itself in wild visions of the height of falls. In Hesiod’s _Theogony_ it is said, speaking of the fall of the Titans into Tartarus, “if a brazen anvil were to fall from heaven nine days and nine nights long, it would reach the earth on the tenth.” This descent of the anvil in 777,600 seconds of time gives an equivalent in distance of 309,424 geographical miles (allowance being made, according to Galle’s calculation, for the considerable diminution in force of attraction at planetary distances); therefore 1½ times the distance of the moon from the earth. But, according to the _Iliad_, Hephæstus fell down to Lemnos in one day; “when but a little breath was still in him.”--_Note to Humboldt’s Cosmos_, vol. iii. RATE OF THE FALL OF BODIES. A body falls in gravity precisely 16-1/16 feet in a second, and the velocity increases according to the squares of the time, viz.: In ¼ (quarter of a second) a body falls 1 foot. ½ (half a second) 4 feet. 1 second 16 ” 2 ditto 64 ” 3 ditto 144 ” The power of gravity at two miles distance from the earth is four times less than at one mile; at three miles nine times less, and so on. It goes on lessening, but is never destroyed.--_Notes in various Sciences._ VARIETIES OF SPEED. A French scientific work states the ordinary rate to be: per second. Of a man walking 4 feet. Of a good horse in harness 12 ” Of a rein-deer in a sledge on the ice 26 ” Of an English race-horse 43 ” Of a hare 88 ” Of a good sailing ship 19 ” Of the wind 82 ” Of sound 1038 ” Of a 24-pounder cannon-ball 1300 ” LIFTING HEAVY PERSONS.