Scientific Dialogues: Intended for the Instruction and Entertainment of Young People, Inwich the First Principles of Natural and Experimental Philosophy are Fully Explained. Vol. II, IV-VI.J. Johnson, 1809 |
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Стр. 199
... needle in a sheet of brown paper , I can read at a very small di- stance indeed . Tutor . You mean , that the let- ters appear , in that case , very much magnified , the reason of which is , that you are able to see at a much shorter ...
... needle in a sheet of brown paper , I can read at a very small di- stance indeed . Tutor . You mean , that the let- ters appear , in that case , very much magnified , the reason of which is , that you are able to see at a much shorter ...
Стр. 226
... the Magnet . TUTOR . You see this dark - brown mineral body , it is almost black , and you know it has the property of at- tracting needles and other small iron substances . James . Yes , it is called a load- stone MAGNETISM The Magnet.
... the Magnet . TUTOR . You see this dark - brown mineral body , it is almost black , and you know it has the property of at- tracting needles and other small iron substances . James . Yes , it is called a load- stone MAGNETISM The Magnet.
Стр. 228
... needle rubbed with a magnet , is freely suspended , it will always , and in all places , stand nearly north and south . Charles . Is it known which end points to the north , and which to the south ? 1 Tutor . Yes : or it would be of 228 ...
... needle rubbed with a magnet , is freely suspended , it will always , and in all places , stand nearly north and south . Charles . Is it known which end points to the north , and which to the south ? 1 Tutor . Yes : or it would be of 228 ...
Стр. 229
... needle always pointing north , the ship must keep m a direction at right angles to the needle . In other words , the direc- tion of the needle must be across the ship . VOL . V. X Charles . Could not the same ob- ject be obtained USE OF ...
... needle always pointing north , the ship must keep m a direction at right angles to the needle . In other words , the direc- tion of the needle must be across the ship . VOL . V. X Charles . Could not the same ob- ject be obtained USE OF ...
Стр. 231
... needle of which being rubbed by the natural or real magnet , becomes possessed of the same properties as those which belong to the magnet itself . Charles . Can any iron and steel be made magnetic ? Tutor . They may ; but steel is the ...
... needle of which being rubbed by the natural or real magnet , becomes possessed of the same properties as those which belong to the magnet itself . Charles . Can any iron and steel be made magnetic ? Tutor . They may ; but steel is the ...
Часто встречающиеся слова и выражения
A B C A B Plate angle of incidence angle of reflection appear attract body called Charles colours compass concave lens concave mirror CONVERSATION convex lens convex mirror dark diameter direction distinct vision diverge double convex equal eye-glass farther feet figure flected focal distance focus of parallel formed half humours inches incident rays inverted image iron James ject lenses Let A B light flowing look looking-glass magnifying power means microscope move nearer needle nosegay object object-glass optic optic nerve painted parallel rays pass pencil of rays perpendicular piece plain mirror Plate 11 proceed radius rainbow rays fall rays flowing rays of light reflected rays reflecting telescope refraction retina seen shutter side small hole south pole spectator stance stand steel Suppose surface throw tion transparent tube Tutor violet vitreous humour
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Стр. 80 - Seasons return, but not to me returns Day, or the sweet approach of ev'n or morn, Or sight of vernal bloom, or summer's rose, Or flocks or herds or human face divine ; But cloud instead, and ever-during dark Surrounds me, from the cheerful ways of men Cut off, and for the book of knowledge fair Presented with an universal blank Of nature's works, to me expung'd and ras'd, And wisdom at one entrance quite shut out.
Стр. 85 - First the flaming red Sprung vivid forth ; the tawny orange next ; And next delicious yellow ; by whose side Fell the kind beams of all-refreshing green. Then the pure blue, that swells autumnal skies, Ethereal...
Стр. 8 - How distant some of these nocturnal suns ! So distant (says the sage) 'twere not absurd To doubt, if beams, set out at nature's birth, Are yet arriv'd at this so foreign world ; Though nothing half so rapid as their flight.
Стр. 109 - ... as the angle of reflection is always equal to the angle of incidence, the image for any point can be seen only in the reflected ray prolonged.
Стр. 166 - Meantime, refracted from yon eastern cloud, Bestriding earth, the grand ethereal bow Shoots up immense; and every hue unfolds, In fair proportion, running from the red To where the violet fades into the sky.
Стр. 172 - Died in the fainting Violet away. These, when the clouds distil the rosy shower, Shine out distinct adown the watery bow ; While o'er our heads the dewy vision bends Delightful, melting on the fields beneath. Myriads of mingling dyes from these result, And myriads still remain ; infinite source Of beauty, ever blushing, ever new. Did ever poet image aught so fair, Dreaming in whispering groves, by the hoarse brook; Or prophet, to whose rapture heaven descends...
Стр. 187 - Yes; the three glasses next the eye baving their focal distances equal, the magnifying power is found by dividing the focal distance of the object-glass by the focal distance of one of. the eye-glasses.
Стр. 49 - A lens is glass ground into such a form, as to collect or disperse the rays of light which pass through it. These are of different shapes, and from thence receive different names.
Стр. 61 - If anoto glass, FG, of the same convexity as DE, be placed in the rays at the same distance from the focus, it will refract them so, as that, after going out of it, they will be all parallel...