American Journal of Science and Arts, Tomy 51-601850 |
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Kluczowe wyrazy i wyrażenia
acid action AGASSIZ alumina American ammonia analysis angle appear atmosphere bismuth carbonate cavity chalk chemical chlorid chymiferous Coast Survey color condensation contains copper core corundum cretaceous crystals currents deposits described diamagnetic diameter direction distance earth effect emery engine eocene equal experiments fact feet feldspar formation formula fossil galvanometer genus geological glass heat helix horizontal force hornblende inches iron Lake Superior less lime limestone magnetic mass metallic mica miles mineral motion mountain nature nearly northern nummulitic observed obtained oxyd oxygen pass peroxyd phenomena Phlogopite piperine planet plates polarity portion potash pounds prehnite present produced Prof protoxyds quantity quartz ratio remarkable ridge river rocks rutile salts sandstone SECOND SERIES seen silica soda species specific gravity specimens spodumene strata substance sulphate sulphuric sulphuric acid surface temperature tion trace tubes variations veins waves weight
Popularne fragmenty
Strona iv - Annual Report of the Regents of the University of the State of New York on the Condition of the State Cabinet of Natural History and the Historical and Antiquarian Collection annexed thereto.
Strona 317 - It must be taken up by the minutest capillaries before it can nourish and purify society. Knowledge is at once the manna and the medicine of our moral being. When crime is the bane, knowledge is the antidote. Society may escape from the pestilence and may survive the famine ; but the demon of Ignorance, with its grim adjutants of vice and riot, will pursue her into her most peaceful haunts, destroying our institutions, and converting into a wilderness the paradise of social and domestic life.
Strona 203 - I have repeated this experiment most anxiously and carefully, but have never obtained the slightest trace of action with the bismuth. I have obtained action with the iron ; but in those cases the action was far less than if the iron were applied outside between the horseshoe magnet and the needle, or to the needle alone, the magnets being entirely away. On using a garnet, or a weak magnetic substance of any kind, I cannot find that the arrangement is at all comparable for readiness of indication...
Strona 341 - The leaf-bud consists of leaves developed in a spiral order ; and in the polyp, as some species show beyond doubt, the tentacles and corresponding parts are spiral in development. The same spiral character is found in the flower, but the volutions are so close as not to be distinguished readily from circles. In the Medusae referred to, the regularly circular form is far more neatly and perfectly developed than among the polyps — as is clearly seen in a comparison of the polyp Coryna with the elegant...
Strona 317 - The cause, therefore, is far advanced ; and every act of liberality to eminent men, and every grant of money for scientific and literary purposes, is a distinct step towards its triumph. Our private institutions have, in reality, assumed the transition phase, and it requires only an electric spark from a sagacious and patriotic statesman to combine in one noble phalanx the scattered elements of our intellectual greatness, and guide to lofty achievements and glorious triumphs the talents and genius...
Strona 97 - From the above-mentioned facts, it must be at once obvious that the various kinds of loose materials, all over the northern hemisphere, have been accumulated, not only under different circumstances, but during long-continued subsequent distinct periods, and that great changes have taken place since their deposition, before the present state of things was fully established. To the first period — the ice period, as I have called it — belong all the phenomena connected with the transportation of...
Strona 385 - ... and in an even and upright position, whilst the nearest approaching wave had its maximum altitude. Here, also, I found at least one half of the waves which overtook and passed the ship were far above the level of my eye. Frequently I observed long ranges (not acuminated peaks) extending 100 yards, perhaps, on one or both sides of the ship, — the sea then coming nearly right aft. — which rose so high above the visible horizon, as to form an angle estimated at two to three degrees (say 2|°)...
Strona 279 - ... miles from the lake, except that of Mr Oswell, in which we travelled the remaining distance ; but for this precaution our oxen would have been unable to return. I am now standing at a tribe of Bakurutse, and shall in a day or two re-enter the desert. The breadth marked is intended to show the difference between the size of the Zonga, after its junction with the Tamunakle and before it. The farther it runs east, the narrower it becomes. The course is shewn by the arrow-heads.
Strona 360 - ... three or four times. The glass is then weighed, after which it is subjected to the same operation as before, the emery being by this time reduced to an impalpable powder. This series of operations is continued until by repeated weighing the loss sustained by the glass is reduced to a few milligrammes. The total loss in the glass is then noted ; and when all the specimens of emery are submitted to this operation under the same circumstances, we get an exact idea of their relative hardness. The...
Strona 179 - With these qualifications, we shall find that, however complicated may be the apparatus, the power will be to the weight in equilibrio as the velocity of the weight to the velocity of the power. As their momenta are equal, there is no increase of force produced by the machinery. This is a proposition, however, which one who is in pursuit of perpetual motion cannot be brought fully to believe till he has learned it by mortifying experience.