Philosophical Transactions of the Royal Society of London, Volumen118

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W. Bowyer and J. Nichols for Lockyer Davis, printer to the Royal Society, 1828
 

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Página 249 - ... communication between this crater and that of Vesuvius: whenever Vesuvius is in an active state, the solfaterra is comparatively tranquil. I examined the bocca of the solfaterra on the 21st of February, 1820, two days before the activity of Vesuvius was at its height: the columns of steam which usually arise in large quantities when Vesuvius is tranquil, were now scarcely visible, and a piece of paper thrown into the aperture did not rise again; so that there was every reason to suppose the existence...
Página 153 - An Account of Trigonometrical Operations in the Years 1821, 1822, and 1823, for determining the Difference of Longitude between the Royal Observatories of Paris and Greenwich.
Página 243 - A measure of it mixed with a measure of nitrous gas gave exactly the same degree of diminution as a measure of common air which had been collected in another bottle on the mountain. I threw upon the surface of the lava nitre, both in mass and in powder. After this salt had fused, there was a little increase of vividness in the ignition of the lava, but much too slight to be referred to pure combustible matter in any quantity ; and on making the experiment on a portion of lava taken up in the ladle,...
Página 109 - ... without increasing the aberration in the first glass beyond the least that can possibly belong to a telescope of the usual kind of the whole length. It should, moreover, be observed, that the adjustment for focus may be made either in the usual way or by a slight movement of the fluid lens, as in the Gregorian reflectors by means of the small speculum. In the latter case the eye-piece is fixed, which may probably be convenient for astronomical purposes, in consequence of the great delicacy of...
Página 247 - ... subterraneous thunder indicated a considerable explosion. Before the eruption, the crater appeared perfectly tranquil; and the bottom, apparently without an aperture, was covered with ashes. Soon, indistinct rumbling sounds were heard as if at a great distance ; gradually the sound approached nearer, and was like the noise of artillery fired under our feet. The ashes then began to rise, and to be thrown out with smoke from the bottom of the crater ; and, lastly, the lava and ignited matter was...
Página 8 - A Treatise on Indigestion, and its consequences, called Nervous and Bilious complaints ; with Observations on the Organic Diseases in which they sometimes terminate; by APW Philip, MDFRS 8vo.
Página 4 - The Creation of the World, with Noah's Flood ; written in Cornish in the Year 1611, by William Jordan; with an English Translation, by John Keigwin. Edited by Davies Gilbert.
Página 249 - To what extent subterraneous cavities may exist even in common rocks, is shown in the limestone caverns of Carniola, some of which contain many hundred thousand cubical feet of air ; and in proportion as the depth of an excavation is greater, so is the air more fit for combustion. The same circumstance which would give alloys of the metals of the earths the power of producing volcanic phenomena, namely, their extreme facility of oxidation, must likewise...
Página 108 - Blair the construction is the same, the fluid having been enclosed in the object-glass itself. Nor could any change in this arrangement in either case be introduced with advantage ; because the dispersive ratio between the glasses in the former instance, and between the glass and fluid in the latter, is too close to admit of bringing the concave correcting medium far enough back to be of any sensible advantage. The case, however, is very different with the sulphuret of carbon. The dispersive ratio...

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