J. W. Phelps

“ The cloud passes on, and often the sinking sun comes out from behind it; the late hushed and frightened birds gush forth with new song; myriad drops hang glittering on the spray; the green is flushed with a brighter, fresher hue, and the glowing rainbow smiles serenely from the dark, retiring, and still grumbling storm. ”

“ Of course, light, as a substance, has nothing to do with the motion. It results entirely from the expansion of the air by the force of heat. Our needle moved on the same principle precisely—and on no other—that the windmill moves in a current of air.
If the glass jar were to be exhausted of its air, and the needle were then to move when struck by a beam of light, the motion might be supposed entirely due to that light; but it may well be doubted whether it is possible to produce a vacuum so perfect that it would be entirely void of gaseous substance of some kind. ”

“ Even thunder-showers are wrested by some men into a political significance!
The circumstances of the case, however, would appear to have been these: A dense cloud, borne upon a low southwest surface-current of wind, was passing across the deep valley of the West River, half a mile or so from its mouth, when it was probably struck by a cool, dry mountain-breeze flowing down the valley. This breeze imparted new electricity to the cloud, which, being thus overcharged, gave out its surplus in a sudden shock, which took effect upon, a group of pines. ”

“ The planetary and starry spaces themselves are probably not entirely free from matter that would respond to the action of heat, if indeed such matter is not necessary for the transmission of light and heat. An infinitesimal portion of air, or even of vapor of mercury, spread through a large jar or receiver, would doubtless obey the same law of expansion under heat that is observed by the atmosphere in its densest conditions, and, when set in motion, would prove sufficient to move a freely-suspended needle. ”

“ The chain of Green Mountains extends throughout the State from south to north, inclining some degrees to the east of north. It presents a barrier to the prevailing general current of southwest wind, and in summer condenses the vapor which that wind bears, thus forming piles of cumulus cloud over the higher summits, or most wooded districts. The deeper ravines, or river-beds, on the eastern slopes of the mountains, run to the southeast, and open out on the wider valley of the Connecticut River. ”

“ In the pursuit of our own method we conceived the idea—which, though a very simple one, was not more simple than some others have been of experimentalists, both before and after the fact—that, if a small needle, say of dry wood, could be suspended from its middle by a torsionless thread, and be excluded from the air, it would retain any fixed direction, while a parallel line under it would change from that direction in proportion as the horizon turned from west to east. ”

“ Yet as to whether the moving force of the thunder-gust is limited wholly to the causes here given, may well admit of a question. It is not improbable that a cloud, from its great height, may penetrate a high upper current from the northwest, and that both this upper and the lower current may contribute to its rapid motion of translation. It is well that these thunder-showers are movable, instead of being stationary, as they often are at sea, for otherwise summer rains would not be evenly distributed over the face of the country ”

“ SOME twenty-five years ago, when Foucault's ingenious experiment for proving the earth's motion on its axis was in vogue, the idea occurred to us that that fact might be proved in another way. Foucault's method, it will be remembered, consisted in the vibration of the pendulum in a fixed direction, the earth's motion being disclosed by the angular deviation of a given chalked line from that direction. ”

“ During a hot summer day the sides of the deep valley of this river reek with intense heat, and cause a flow of moist air upward toward the summits of the mountain-ridge, from the valley of the Connecticut, and also from the sea. ”