NOTE I … METEORS.
There are four strata of the atmosphere, and four kinds of meteors. 1. Lightning is electric, exists in visible clouds, its short course, and red light. 2. Shooting stars exist in invisible vapour, without sound, white light, have no luminous trains. 3. Twilight; fire-balls move thirty miles in a second, and are about sixty miles high, have luminous trains, occasioned by an electric spark passing between the aerial and inflammable strata of the atmosphere, and mixing them and setting them on fire in its passage; attracted by volcanic eruptions; one thousand miles through such a medium resists less than the tenth of an inch of glass. 4. Northern lights not attracted to a point but diffused; their colours; passage of electric fire in vacuo dubious; Dr. Franklin's theory of northern lights countenanced in part by the supposition of a superior atmosphere of inflammable air; antiquity of their appearance; described in Maccabees.