To assist the imagination in forming an idea of the vast distances of the sun, planets, and stars, let us suppose, that a body projected from the sun should continue to fly with the swiftness of a cannon-ball, i. e. 480 miles every hour;

this body would reach the orbit of Mercury in 7 years 221 days; of Venus, in 14 years 8 days; of the earth, in 19 years 91 days; of Mars, in 29 years 85 days; of Jupiter, in 100 years 280 days; of Saturn, in 184 years 240 days;

to the comet of 1680, at its greatest distance from the sun, in 2660 years; and to the nearest fixed stars, in about 7 million 600 thousand years.