Manual of Mineralogy, Including Observations on Mines, Rocks, Reduction of Ores, and the Applications of the Science to the Arts ... for the Use of Schools and Colleges

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H.H. Peck, 1869 - 454 Seiten
 

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Seite 411 - Also, 4 inches are 1 hand; 6 feet 1 fathom; -40 rods 1 furlong ; 8 furlongs 1 mile ; 3 miles 1 league.
Seite 357 - To be a good material for roofing, it should split easily into even slates, and admit of being pierced for nails without fracturing, Moreover, it should not be absorbent of water, either by the surface or edges, which may be tested by weighing, after immersion for a while in water. It should also be free from pyrites, and every thing that can undergo decomposition on exposure.''* FLAGSTONES.
Seite 215 - Cornwall was called, it is supposed from the horn shape of this western extremity of England.) The Greeks residing at Marseilles were the next to visit Cornwall, or the isles adjacent, to purchase tin ; and after them came the Romans, whose merchants were long foiled in their attempts to discover the tin market of their predecessors. Camden says : " It is plain that the ancient Britons dealt in tin mines from the testimony of Diodorus Siculus, who lived in the reign of Augustus and Timaus, the historian...
Seite 49 - ... be produced in the same direction ; then the sum of the exterior angles A, B, C, D, E, will be equal to four right angles. For each interior angle, together with its adjacent exterior angle, is equal to two right angles (Prop.
Seite 311 - Extraction of Palladium in Brazil. The extraction of palladium, from the auriferous sand of Brazil, consists in fusing it with silver, and, consequently, forming a quaternary alloy of gold, palladium, silver, and copper, which is granulated by projecting it into water. By treating this alloy with nitric acid, the gold is separated from the other metals which are soluble in the acid; the silver is precipitated by a solution of common salt in the state of insoluble chloride, which being separated,...
Seite 81 - The rocks in which the diamond occurs in Brazil are either a ferruginous quartzose conglomerate, or a laminated granular quartz called Itacolumite. The latter rock occurs in the Urals, and diamonds have been found in it ; and it is also abundant in Georgia and North Carolina. In India the rock is a quartzose conglomerate.
Seite 85 - ... generally divides it into two varieties : — First, Coal without Bitumen. Second, Coal with Bitumen. The first variety is known by the general name of Anthracite. It has however various local names. [ANTHRACITE.] It is sometimes very hard, and has a high lustre, and is often iridescent. Besides being used for fuel it is often made into inkstands, small boxes, and other articles of use. This is more especially the case with the Anthracite of America. It is the most common form of coal in the...
Seite 351 - When i» contains hornblende in place of mica, it is called syenite , hornblende resembles mica in these rocks but the laminae separate much less easily and are brittle. Granite is said to be micaceous, feldspathic, or quartzose, according as the mica, feldspar, or quartz, predominates. It is called porphyritic granite, when the feldspar is in large crystals, and appears over a worn surface like thickly scattered white blotches, often rectangular in shape. Graphic granite has an appearance of small...
Seite 361 - such was the care of the ancients to provide strong and durable materials for their public edifices that but for the desolating hands of modern barbarians, in peace and in war, most of the temples and other public monuments of Greece and Rome would have remained perfect at the present day, uninjured by the elements during two thousand years.
Seite 257 - Wrought iron is changed to steel by a process called cementation. The best iron is heated with charcoal ; a portion of carbon is thus absorbed, and the iron at the same time acquires a blistered surface, and becomes fine grained and fusible. When the blistered steel is drawn down into smaller bars and beaten, it forms tilted steel; and this broken up, heated, welded, and again drawn out into bars, forms shear steel. Cast steel is prepared by fusing blistered steel with a flux and casting it into...

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