Mineralogia Cornubiensis: A Treatise on Minerals, Mines, and Mining: Containing the Theory and Natural History of Strata, Fissures, and Lodes, with the Methods of Discovering and Working of Tin, Copper, and Lead Mines, and of Cleansing and Metalizing Their Products; Shewing Each Particular Process for Dressing, Assaying and Smelting of Ores. To which is Added, an Explanation of the Terms and Idioms of Miners
Printed and sold for the author by J. Phillips, 1778 - 331 من الصفحات
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الصفحة 18 - On the proud crest of Satan, that no sight, Nor motion of swift thought, less could his shield, Such ruin intercept : Ten paces huge He back...
الصفحة 311 - The condenfer confifts of one or more pumps furnifhed with clacks and buckets, (nearly the fame as in common pumps) which are wrought by chains faftened to the great working beam of the engine. The pipe, which comes from the cylinder, is joined ;to the bottom of thefe pumps, and the whole condenfer ftands immerfed in a ciftern of cold water fupplied by the engine.
الصفحة 118 - The rod should be firmly and steadily grasped -, for if, when it has begun to be attracted, there be the least imaginable jerk or opposition to its attraction, it will not move any more till the hands are opened, and a fresh grasp taken. The stronger the grasp the livelier the rod moves, provided the grasp be steady and of an equal strength.
الصفحة 13 - All the rivers run into the sea, yet the sea is not full ; unto the place from whence the rivers came, thither they return again.
الصفحة 311 - The cylinder is fmaller than ufual, in proportion to the load, and is very accurately bored. In the moft complete engines it is furrounded, at a fmall diftance, with another cylinder, furnifhed with a bottom and a lid. The interftice between the cylinders communicates with the...
الصفحة 310 - He lias contrived to observe an uniform heat in the cylinder of his engines, by suffering no cold water to touch it, and by protecting it from the air, or other cold bodies, by a surrounding case filled with...
الصفحة 112 - Where metals ripen in vaft cakes of ore. Here, fullen to the fight, at large is fpread The dull unwieldy mafs of lumpifh lead. There, glimmering in their dawning beds, are feen 75 The light afpiring feeds of fprightly tin.
الصفحة 312 - Ib raifes the buckets of the pumps which are hung to the other end of the beam. The exhauftion regulator is now fhut, and the fteam one opened again, which, by letting in the fteam, allows the pifton to be pulled up by the fuperior weight of the pump rods; and fo the engine is ready for another ftroke.
الصفحة 46 - Essays, iv. p. 34. Pryce, in Mineral. Cornub., p. 49, says, " The late Dr. J. Lawson, observing that the flowers of lapis calaminaris were the same as those of zinc, and that its effects on copper were also the same with that semi-metal, never remitted his endeavours till he found the method of separating pure zinc from that ore.