Transactions of the Geological Society of London

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Página 2 - TRANSACTIONS of the Society instituted at London for the Encouragement of Arts, Manufactures and Commerce, with the Premiums offered in the year 1783.
Página 14 - The regular and uniform preservation of this thin bed of black earth over a distance of many miles, shows that the change from dry land to the state of a freshwater lake or estuary, was not accompanied by any violent denudation, or rush of water, since the loose black earth, together with the trees which lay prostrate on its surface, must inevitably have been swept away had any such violent...
Página 412 - Gawilghur it appears stratified, the summits of several ravines presenting a continued stratum of many thousand yards in length. As Colonel Sykes accurately remarks, there does not appear to be any uniformity in the alternation of the strata, "but the general level, thickness, and extent of a stratum are preserved, as in sedimentary rocks, on both sides of a valley; the basalt and hardest amygdaloid being traceable for miles in the parallel spurs or ranges ; but the imbedded minerals, and even the...
Página 417 - Causeway in Ireland. It passes through every variety of texture, from pulverulent, friable, and indurated, to compact earthy jasper. The stratum is from an inch in thickness to many feet. The rock makes a red streak on paper, with the exception of the very indurated kinds, and does not affect the needle. It is pulverulent near the basaltic columns at Serroor, friable under sub-columnar red amygdaloid, near the source of the Seena river, indurated under basalt at Kothool. Although hard, it is here...
Página 14 - Trees of America, Native and Foreign, Pictorially and Botanically Delineated, and Scientifically and Popularly Described ; being considered principally with reference to their Geography and History; Soil and Situation ; Propagation and Culture ; Accidents and Diseases ; Properties and Uses : Economy in the Arts ; Introduction into Commerce ; and their Application in Useful and Ornamental Plantations.
Página 9 - Treatise on Nautical Surveying; containing an Outline of the Duties of the Naval Surveyor, with Cases applied to Naval Evolutions, and Miscellaneous Rules and Tables useful to the Seaman or Traveller. Plans and Plates. 8° London, 1835. - Directions for the Eiver Douro, 1833. 8
Página 417 - Ahmednuggur, in the valley of the Godavery river, it is found as a porphyritic stratum many feet in thickness, and is used as a building stone. The imbedded matter consists of very minute crystals of lime. At Wangee, lying nearly in the latitude of Barlonee, but differing...
Página 422 - ... observed the same peculiar stratum near Sagar. He says, " There occurs an amygdaloidal or porphyritic rock, consisting of a compact basis of wacke, in which are imbedded in great abundance small globular or uniform masses, but more usually long, curved, cylindrical, or vermiform crystals of zeolite." The other rock occurs as a thick stratum of amygdaloid, at the elevation of 4000 feet, in the hill forts of Hurreechundurghur and Poorundhur, and in the bed of the Goreh River at 1800 feet, near...
Página 420 - ... and with a disposition to determinate forms, are piled upon each other, constituting rude pillars. In certain parts of the country from fifty to sixty of these heaps are seen within the area of a couple of square miles, and it excites surprise that the intermediate ground is destitute of stones. Sheets of Rock. Mention must not be omitted of the constant recurrence of sheets of rock of considerable extent at the surface, and totally destitute of soil : this is particularly the case in the Mawals,...
Página 235 - ... since it is easily dressed in the rough, and grinds away faster in the finishing process. The method of manufacturing the Cretaceous sandstones at Blackdown, England, is told in an entertaining manner in the Transactions of the Geological Society of London for 1836.* The writer says : "When first taken the stone is greenish and moist, and can be cut or chopped with ease. The tools employed are a sort of adze called a basing hammer. The others are ordinary picks and shovels. A vertical post or...

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