Library of Useful Knowledge: Natural philosophy, Volume 11829 |
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Page 22
... , if a pair The feathers of the wings of birds are found to be placed at the best possible angle for helping on the bird by their action on the air . of spectacles be held between a candle and the wall 22 36 OBJECTS , ADVANTAGES , AND.
... , if a pair The feathers of the wings of birds are found to be placed at the best possible angle for helping on the bird by their action on the air . of spectacles be held between a candle and the wall 22 36 OBJECTS , ADVANTAGES , AND.
Page 25
... angle must be 109 ° 28 ' , and the acute 70 ° 32 ' , to save the most wax and work possible . Maraldi found , by actual measure ment , that the angles are about 1100 and 700. These angles never vary in any place ; and it is scarcely ...
... angle must be 109 ° 28 ' , and the acute 70 ° 32 ' , to save the most wax and work possible . Maraldi found , by actual measure ment , that the angles are about 1100 and 700. These angles never vary in any place ; and it is scarcely ...
Page 25
... Angle with the axis . 72 ° 71 72 Angle with the plane of the motion . 18 ° 19 18 74 16 77 83 12 7 ( 56. ) The last property , in virtue of which we have stated that air becomes a mechanical agent , is its elasticity . The nature of this ...
... Angle with the axis . 72 ° 71 72 Angle with the plane of the motion . 18 ° 19 18 74 16 77 83 12 7 ( 56. ) The last property , in virtue of which we have stated that air becomes a mechanical agent , is its elasticity . The nature of this ...
Page 14
... angles , and Sc should be equal to S'c . The beam being thus constructed , the point g will , by the properties of the ... angle S ca. Let the position of the points S and S ' on the vertical plane against which the beam is suspended be ...
... angles , and Sc should be equal to S'c . The beam being thus constructed , the point g will , by the properties of the ... angle S ca. Let the position of the points S and S ' on the vertical plane against which the beam is suspended be ...
Page 15
... angle S'c S will be the deviation of the line Sc or SS ' from the perpendicular aa ' . ( 37. ) A process somewhat similar to this serves to determine the deviation of the index from the direction of the line gm ( fig . 24. ) Suppose ...
... angle S'c S will be the deviation of the line Sc or SS ' from the perpendicular aa ' . ( 37. ) A process somewhat similar to this serves to determine the deviation of the index from the direction of the line gm ( fig . 24. ) Suppose ...
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Common terms and phrases
Acid angle angle of incidence apophyllite atmosphere axes axis axle beam blue body boiling Brewster called caloric centre of gravity circle circumference colours column convex convex lens crown glass crystals curve cylinder degree diameter diminished direction distance double refraction effect elastic equal equilibrium experiments Fahrenheit feet flint glass fluid force friction glass greater green heat Hence increased index of refraction length lens lever liquid machine mechanical mercury motion move observed parallel particles pass perpendicular pipe piston placed plane plate polarised light portion position pounds pressure prism produced properties proportion pump quantity rays reflected reflexion resistance retina rope round screw side solid space specific gravity square inch steam substance suppose surface system of rings temperature thermometer thickness tints tion tube valve vapour velocity vessel violet weight wheel yellow
Popular passages
Page 20 - ... is equal to the weight of a column of water whose base is the section of the piston, and whose height is the distance of the level of the water in the barrel AC, above the level in the reservoir.
Page 51 - so well defined, that I could distinguish, by a telescope, every sail, the general rig of the ship, and its particular character, insomuch that I confidently pronounced it to be my father's ship, the Fame, — which it afterwards proved to be — though on comparing notes with my father, I found that our relative position, at the time, gave our distance from one another very nearly thirty miles, being about seventeen miles beyond the horizon, and some leagues beyond the limit of direct vision!
Page 37 - Can any thing surprise us more, than to find that the color of white is a mixture of all others; that red, and blue, and green, and all the rest, merely by being blended in certain proportions, form what we had fancied rather to be no color at all than all colors together? Chemistry is not behind in its wonders. That the diamond...
Page 38 - Is it not in the highest degree interesting to find, that the power which keeps this earth in its shape, and in its path, wheeling round the sun, extends over all the other worlds that compose the universe, and gives to each its proper place and motion ; that...
Page 40 - Providence, every part would be in harmony with a plan of absolute benevolence. Independently, however, of this most consoling inference, the delight is inexpressible of being able to follow, as it were, with our eyes, the marvellous works of the Great Architect of Nature, to trace the unbounded power and exquisite skill which are exhibited in the most minute, as well as the mightiest parts of his system.
Page 32 - This will cause the air at the equator to stand more than seven miles higher from the surface of the earth to the top of the atmosphere than at the north pole.
Page 39 - ... and reasoning, of some of the great doctrines in Natural Science, learning truths wholly new to him, and satisfying himself by careful examination of the grounds on which known truths rest, so...
Page 37 - How wonderful are the laws that regulate the motions of fluids ! Is there anything in all the idle books of tales and horrors more truly astonishing than the fact, that a few pounds of water may, by mere pressure, without any machinery — by merely being placed in a particular way, produce an irresistible force? What can be more strange, than that an ounce weight should balance hundreds of pounds, by the intervention of a few bars of thin iron? Observe the extraordinary truths which Optical Science...
Page 50 - ... in their natural colours and proper actions, passing rapidly in succession along the surface of the sea during the whole of the short period of time while the above-mentioned causes remain.
Page 38 - ... plants and animals to breathe ; that these operations, so unlike to common eyes, when examined by the light of science, are the same, — the rusting of metals, — the formation of acids, — the burning of inflammable bodies, — the breathing of animals, — and the growth of plants by night. To know this is a positive gratification.