Scientific Dialogues,: Of mechanics

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Baldwin and Cradock; and R. Hunter, 1828

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Page 178 - Soon shall thy arm, unconquered steam, afar Drag the slow barge, or drive the rapid car ; Or on wide waving wings expanded bear The flying chariot through the fields of air ; — Fair crews triumphant, leaning from above, Shall wave their fluttering kerchiefs as they move, Or warrior bands alarm the gaping crowd, And armies shrink beneath the shadowy cloud.
Page 186 - The mercury is sustained in the tube by the pressure of the atmosphere on the surface of the fluid in the cup.
Page 240 - ... 1. The rising of the mercury presages, in general, fair weather, and its falling foul weather, as rain, snow, high winds, and storms.
Page 90 - Perhaps this is speaking rather too positively, if there be, as I think there are, some other mediums that will convey it farther and more readily. It is a well-known experiment, that the scratching of a pin at one end of a long piece of timber, may be heard by an ear applied near the other end, though it could not be heard at the same distance through the air. And two stones being struck smartly together under water, the stroke may be heard at a greater distance by an ear also placed under water...
Page 124 - Rossneath, near Glasgow, there is an echo that repeats a tune played with a trumpet three times completely and distinctly. Near Rome there was one that repeated what a person said five times. At Brussels there is an echo that answers 15 times.
Page 157 - NYMPHS ! you erewhile on simmering caldrons play'd, And call'd delighted Savery to your aid ; Bade round the youth explosive Steam aspire, In gathering clouds, and wing'd the wave with fire ; Bade with cold streams the quick expansion stop, And sunk the immense of vapour to a drop. Press'd by the ponderous air the piston falls Resistless, sliding through its iron walls ; Quick moves the balanced beam, of giant birth, Wields his large limbs, and nodding shakes the earth.
Page 183 - It was heard at a considerable distance, and actually shook the house. The bottom of the vessel that was in the fire gave way ; the blast of the expanded water blew all the coals out of the fire into the room, the remainder of the vessel flew across the room, and hitting the leaf of an oak table, an inch thick, broke it all in pieces, and rebounded half the length of the room back again.
Page 240 - When the surface of the mercury is convex, or stands higher in the middle than at the sides, it is a sign the mercury is then in a rising state; but if the surface be concave or hollow in the middle it is then sinking.
Page 241 - In fair weather, when the mercury falls much and low, and thus continues for two or three days before the rain comes, then expect a great deal of wet, and probably high winds.
Page 178 - At the cannon foundry in Moorfields, hot metal •was poured into a mould that accidentally contained a small quantity of water, which was instantly converted into steam, and caused an explosion that blew the foundry to pieces. A similar accident happened at a foundry in Newcastle, which occurred from a little water having insinuated itself into a hollow brass ball that was thrown into the melting pot.

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