How Thunder Showers Come Up

In order To coovcy a more defimte idea of our theory, we will choose acortain locality whieh may serve the purpo3e of a diagram toourdeinonstrations ; andthis locality shall be tho región of West river. This river takes its rise atnong tbe forosts near the Miiiiniit of tho Green Mountains, at a hight of some twothousand feet above the level of the sea, and flowing southerly forty or fifty miles, euipties into the Connecticut rivcr, about two miles north from the Southern boundry of the state. During a hot summer day, the sides of the deep valley of this river reek with intense heat, aod cauBC a flow of moist air upward toward the summit of the mountain región, from the valley of the Coiinec cicut, and also from the sea. This moist air, meeting with the general curretit from the southweüt, piles up an immense mass of cumulus cloud of many miles in extent. So long as the intense heat prevails, this cloud increases in siza : grows blacker with its dense vapor, and casts a gloouiy, lurid filare over the face of nature, darker than that of any eclipse. The vapor, ptubed by the ascending currents of heated air, attains a greatheight above the seo, where the temperature is very low. But finally, at that hour of the afternoon when the heat begins to decline, the nccumulated vapora, no longer augmented or sustained by hcatcd air from the valleys below, fmll ia rain.