Philosophical Transactions of the Royal Society of London, Volumen 119W. Bowyer and J. Nichols for Lockyer Davis, printer to the Royal Society, 1829 |
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Página 9
... greater extent of field they present to view at once , whereby they are admirably adapted to make an entertaining exhibition of known objects , hardly any one of the compound microscopes which I have yet seen , is capable of exhibiting ...
... greater extent of field they present to view at once , whereby they are admirably adapted to make an entertaining exhibition of known objects , hardly any one of the compound microscopes which I have yet seen , is capable of exhibiting ...
Página 20
... greater than that of the moon * ; and consequently the direct light of the sun as very many millions times greater than that afforded us by all the fixed stars , taken collectively . Such then being , to our visual organs , the vast ...
... greater than that of the moon * ; and consequently the direct light of the sun as very many millions times greater than that afforded us by all the fixed stars , taken collectively . Such then being , to our visual organs , the vast ...
Página 43
... greater force . By a slight adjustment of the length of the chain and weight , we may thus produce a perfect equilibrium in the whole machine , and the telescope is of course obedient to the slightest power sufficient to overcome the ...
... greater force . By a slight adjustment of the length of the chain and weight , we may thus produce a perfect equilibrium in the whole machine , and the telescope is of course obedient to the slightest power sufficient to overcome the ...
Página 51
... greater portability : except in size , the whole apparatus is in all respects similar to the one with which the observations already detailed were made . The agate supports are levelled in the same manner by a circular plate carrying a ...
... greater portability : except in size , the whole apparatus is in all respects similar to the one with which the observations already detailed were made . The agate supports are levelled in the same manner by a circular plate carrying a ...
Página 60
... greater proportion , than might be expected to have occurred from small - pox alone ; and the well - known uprightness of his character , entitles this opinion to every degree of credit . Hence , in strict correctness , they do not ...
... greater proportion , than might be expected to have occurred from small - pox alone ; and the well - known uprightness of his character , entitles this opinion to every degree of credit . Hence , in strict correctness , they do not ...
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altitudes ammonia angle of incidence appears arch azote Barom Barometer blue calculous cast iron circle clear-light Clock clouds Coincid Comet Corrected Vibrations cubic inches Culmination Disapp experiments feet fifth nerve Fine-light fluid friction ganglion glass Half Diff Inferior Culminat July June Latitude light limb lime lithate of ammonia lithic acid lithotomy logarithms Lond Longitude MDCCCXXIX Mean Mean Mean Mean Refract Mean S. P. D. meridian metal Microscopes motion mural circle muriate muscles nearly needle nervous nutation observations Observatory Octantis Overcast Paramatta pendulum phosphate pink plate platina pressure prism prismatic images proportion quantity rarefied medium Re-app Reduct reflected right ascensions Royal Society SABINE screwed Sept Sidereal Sirius Solstice stars streamers Sun's Superior Culminat surface temperature Therm Thermometers THOMAS BRISBANE tion true Arc vibrations per diem weight wind yellow zenith distance دو وو
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Página 366 - TRANSACTIONS of the Society instituted at London for the Encouragement of Arts, Manufactures and Commerce, with the Premiums offered in the year 1783.
Página 18 - In order, however, to guard effectually against cavities, the barrel may be weighed after filling it, and the actual weight of its contents being thus ascertained, may be compared with that weight of platina and water which it is known by estimate that the barrel ought to contain *. A circular piece of soft paper first, and then of woollen cloth, being laid upon the surface, allow the water to pass, during partial compression by the force of the hand with a wooden plug. A circular plate of copper...
Página 17 - I have used for casting, is a brass barrel, 6f inches long, turned rather taper within, with a view to facilitate the extraction of the ingot to be formed, being 1.12 inches in diameter at top, and 1.23 inches at a quarter of an inch from the bottom, and plugged at its larger extremity with a stopper of steel, that enters the barrel to the depth of a quarter of an inch. The inside of the mould being now well greased with a little lard, and the stopper being fitted tight into the barrel by surrounding...
Página 22 - Hence it is clear that an under current outward of such denser water, if of equal breadth and depth with the current inward near the surface, would carry out as much salt below as is brought in above, although it moved with less than one fourth part of the velocity, and would thus prevent a perpetual increase of saltness in the Mediterranean Sea beyond that existing in the Atlantic.
Página 6 - The centre of this aperture must be in the common axis of the lenses ; and the image of the perforation formed by the large lens must be brought, by proper adjustment of the distance of that lens, into the same plane as the object to be examined. With a microscope so constructed, the author has seen the finest striae and serratures upon the scales of the lepisma and podura, and the scales upon a gnat's wing, with a degree of delicate perspicuity not attainable with any other microscope he has tried....
Página 137 - ... and in a subsequent paper, illustrated by some experiments on wood and metals pressed by springs of known intensity, he drew similar conclusions, with the addition that friction was one-third of the pressure, and that the amount was the same both with wood and metals when unguents were interposed. He likewise concluded, that friction increased or diminished with the velocity, and varied in the ratio of the weight and pressure of the rubbing parts, and the. times and velocities of their motions....
Página 3 - ... and brought to the eye, beyond that which is fully commanded by the object-glasses, tends rather to impede than to assist distinct vision. My endeavour has been, to collect as much of the admitted light as can be done by simple means, to a focus in the same plane as the object to be examined. For this purpose I have used with success a plane mirror to direct the light, and a plano-convex lens to collect it ; the plane side of the lens being towards the object to be illuminated.
Página 3 - A treatise on navigation by steam; comprising a history of the steam engine, and an essay towards a system of the naval tactics peculiar to steam navigation, as applicable both to commerce and maritime warfare.