The Quarterly Journal of the Geological Society of London, Volumen 65The Society, 1909 Vols. 1-108 include Proceedings of the society (separately paged, beginning with v. 30) |
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Términos y frases comunes
abundant andesitic appears Arenig Bala band beds boulders breccia calcareous Carboniferous cherts chlorite cliffs Climacograptus coarse conglomerate Conway County Clare crystals cwms Deganwy deposits described dykes east erosion evidence exposed exposures fault fault-intrusion fauna feet felsite felspar flags folds fossils Geol Geological Gill glacial glaciers Glen Coe gorge granite graptolites grits gritty ground-mass holotype horizon inches intrusion Journ junction Lapw later lavas limestone lines of growth Llandeilo Lower Loxonema M'Coy margin mass matrix mile mineral Monograptus mountains mudstones nodules normal numerous occur Orthis outcrop phenocrysts Phyllites plagioclase pleuræ Pont Erwyd porphyrite pre-Glacial Prof pygidium pyroxene quarry quartz quartzite rhyolites ridge river rocks Sandstone schists seen shales Shangort side sinuosum slope Snowdon district species specimens strata stream structure thickness Tourmakeady tuffs Upper valley volcanic Wales whorls yards zone
Pasajes populares
Página xxiv - Not less than one third of the annual interest to accompany the medal, the remaining interest to be given in one or more portions at the discretion of the Council for the encouragement of geology or of any of the allied sciences by which they shall consider geology to have been most materially advanced...
Página 320 - By this correction of his first opinion, a new approximation is made to the truth; and by the repetition of the same process certainty is finally obtained. Thus theory and observation mutually assist one another; and the spirit of system, against which there are so many and such just complaints, appears, nevertheless, as the animating principle of inductive investigation. The business of sound philosophy is not to extinguish this spirit, but to restrain and direct its efforts.
Página xxiv - to be cast in bronze and to be given annually ' (or from time to time) 'as a mark of honorary distinction and as an expression on the part of the governing body of the Society that the Medallist (who may be of any country or either sex) has deserved well of the Science...
Página 320 - ... of theory is necessary to direct the observer. Though a man may begin to observe without any hypothesis, he cannot continue long without seeing some general conclusion arise, and to this nascent theory it is his business to attend, because, by seeking either to verify or to disprove it, he is led to new experiments or new observations. He is led also to the very experiments and observations that are of the greatest importance, namely, to those instantice crucis, which are the criteria that naturally...
Página 320 - ... which are the criteria that naturally present themselves for the trial of every hypothesis. He is conducted to the places where the transitions of nature are most perceptible, and where the absence of former, or the presence of new circumstances, excludes the action of imaginary causes. By this correction of his first opinion, a new approximation is made to the truth ; and by the repetition of the same process, certainty is finally obtained. Thus theory and observation mutually assist one another...
Página 320 - The truth, indeed, is, that in physical inquiries, the work of theory and observation must go hand in hand, and ought to be carried on at the same time, more especially if the matter is very complicated, for there the clue of theory is necessary to direct the observer.
Página xxvi - as an acknowledgment of eminent services in any department of Geology, irrespective of the receiver's country ; but he must not be older than 45 years at his last birthday, thus probably not too old for further work, and not too young to have done much.
Página 310 - Furthermore, (f) there can be no more groups of hanging side-valleys than there are rock-steps in the main valley floor; and all the members of a group of hanging side-valleys must occur between two successive rock-steps in the main valley-floor. On the other hand, (g) large or small lateral valleys not occupied to the mouth with sideglaciers, must enter the main valley at accordant level with it, and yet they may be in close neighbourhood with hanging lateral valleys.
Página xx - to promote researches concerning the mineral structure of the earth, and to enable the Council of the Geological Society to reward those individuals of any country, by whom such researches may hereafter be made.
Página xlix - Such metamorphosed or fused masses were sometimes more or less completely broken up by violent collision, and the fragments again collected together and solidified. Whilst these changes were taking place, various metallic compounds of iron were so introduced as to indicate that they still existed in free space in the state of vapor, and condensed amongst the previously formed particles of the meteorites.