OCR Text |
Show 506 Configure: 450212" the Aurora Borealis. [M.P.] Cou/efiurerauout theAurora Borealis. 507 10. If the rain be received in an ifolated veffel, the veffel will be electrified ; for every drop to. The humidity contained in all the equatorial clouds that reach the pol ar revions mutt there be condenfed and fall in fno w. D , 2o. The great cake of ice that eter nally covers thole regions may be too hard fro zen the electricity, defcending with that to permit fnow ~f~ to enter the earth. I brings down fome electricity with it. I I. The fame is done by [now or hail. 12. The electricity fo defcending, in temperate 1‘ climates, is received and imbibed by the earth. 13. If the clouds are not futliciently difcharged by this gradual operation, they fometimes difcharge themfelves fuddenly by ftriking into the ' 21. It may therefore be urcumu/az‘ud upon t/Jut m. earth, where the earth is fit to receive their elec- is generally fit to receiveit, being a good conduc- 22. The atmofphere being heavier in the polar regions, than in the equatorial, will there be lower; as well from that caufe, as from the [ma]- tor. ler effect ofthe centrifugal force : confequently the 1 5. A certain quantity of heat will make fome bodies good conductors, that will not otherwife dif'tance of the vacuum above the atmofphe re will be lefs at the poles, than elfewhere; and prob ably much lefs than the dif'tance (upon the fur-fa ce of conduct. the globe) extending from the pole to thofe lati- tricity. 14. The earth in temperate and warm climates 16. Thus wax rendered fluid, and glafs foften- ed by heat, will both of them conduct. 17. And water, though naturally a good con- ductor, will not conduct well, when frozen into ice by a common degree of cold ; not at all, where the cold is extreme 1-. tudes in which the earth is {0 thawed as to receive and imbibe electricity; (the frof't continuing to lat. 80 i, which is ten degrees, or 600 miles from the pole; while the height of the atmofphere there of fuch denfity as to obf'trué't the motion H of the electric fluid, can fearce be ef'reemed above [ 18. Snow falling upon frozen ground has been ] miles). 23. The vacuum above is a good conductor a". found to retain its electricity 5 and to commum- cate it i to an ifolated body, when after falling, it has been driven about by the Wind. 19. The 24. May not then the great quantity of electricity, brought into the polar regions by the clouds, which are condenfed there, and fall in fnow, which electricity would enter the earth, T tt 2 but "Illrlllililllllllllll‘ll |