A Compleat System of Opticks in Four Books, Viz. A Popular, a Mathematical, a Mechanical, and a Philosophical Treatise. To which are Added Remarks Upon the Whole. By Robert Smith, Volumen1author, and sold there, 1738 - 171 páginas |
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Página xii
... whose aper- ture and eye - glafs are adjusted by experience , to determine the length , aperture and eye - glass of another telescope , thro ' which an object fhall appear as bright and distinct as in the given one , and magnified as ...
... whose aper- ture and eye - glafs are adjusted by experience , to determine the length , aperture and eye - glass of another telescope , thro ' which an object fhall appear as bright and distinct as in the given one , and magnified as ...
Página 18
... whose nearest distance from the decanter will be equal to a femidiameter of the belly of it : as will appear by receiving the rays . upon a paper held at that diftance . That this effect is owing to the re- fraction of the water and not ...
... whose nearest distance from the decanter will be equal to a femidiameter of the belly of it : as will appear by receiving the rays . upon a paper held at that diftance . That this effect is owing to the re- fraction of the water and not ...
Página 19
... whose distance from D is one third of its distance from C ; that is , CT b Art . 57 . is to TD as 3 to 1 and confequently CT is to TE as 3 to 2 , as was faid in the 33d article . If the experiment be tryed with a lighted candle pla- ced ...
... whose distance from D is one third of its distance from C ; that is , CT b Art . 57 . is to TD as 3 to 1 and confequently CT is to TE as 3 to 2 , as was faid in the 33d article . If the experiment be tryed with a lighted candle pla- ced ...
Página 27
... whose greater tenfion helps to flatten it , may perhaps be flackened by the lateral preffure a- forefaid ; and poflibly both thefe alterations are made at the fame time . The hole or pupil O is not placed in the center of the cornea ABC ...
... whose greater tenfion helps to flatten it , may perhaps be flackened by the lateral preffure a- forefaid ; and poflibly both thefe alterations are made at the fame time . The hole or pupil O is not placed in the center of the cornea ABC ...
Página 28
... whose eyes are too plump . For the refraction being now too great , the rays converge and convene in thefe eyes before they come at the bottom ; and therefore and mended the picture made in the bottom and the vision caufed thereby will ...
... whose eyes are too plump . For the refraction being now too great , the rays converge and convene in thefe eyes before they come at the bottom ; and therefore and mended the picture made in the bottom and the vision caufed thereby will ...
Términos y frases comunes
aberration alfo alſo altitude angle of incidence aperture apparent diftance apparent magnitude appear arch axis bafe becauſe breadth brightneſs cafe caufe cauftick cauſe circle cofine colours concave confequently convex Corol corona curve cylinders decreaſe defcribed denfity diameter diftinct diminiſhed emergent rays equal eye-glafs fame feen femidiameter fhall fhape fhews fide fince fingle firſt fituation fmall focal diſtance focus focuſes fome fquare ftraight fubtends fucceffive fuch fun's fuppofing furface given glaffes glafs glaſs globules Hence horizon incident rays increaſe interfection inverted laft laſt lefs lens light meaſured microſcope muſt obferved object obliquely optick paffing parallel parhelia parhelion pencil perpendicular placed plane pofition prifm produced propofition ratio reafon reflected refracted rays refrangible reprefented retina ſeen ſmall ſphere ſpherical tangent teleſcope thefe theſe thofe thoſe triangles vertical whofe
Pasajes populares
Página 43 - He knew not the shape of any thing, nor any one thing from another, however different in shape, or magnitude, but upon being told what things were, whose form he before knew from feeling, he would carefully observe, that he might know them again; but having too many objects to learn at once, he forgot many of them : and (as he said) at first he learned to know, and again forgot a thousand things in a day.
Página 43 - One particular only (though it may appear trifling) I will relate. Having often forgot which was the cat, and which the dog, he was ashamed to ask ; but catching the cat (which he knew by feeling) he was observed to look at her steadfastly, and then setting her down, said, so puss ! I shall know you another time.
Página 74 - I speak of Light and Rays as coloured or endued with Colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such Conceptions as vulgar People in seeing all these experiments would be apt to frame. For the Rays to speak properly are not coloured.
Página 43 - ... a glass of broken jelly, where a great variety of surfaces so differently refract the light, that the several distinct pencils of rays cannot be collected by the eye into their proper foci ; wherefore, the shape of an object in...
Página xiv - France and Ireland Defender of the Faith &c. To all to whom thefe Prefents fhall come Greeting.
Página 89 - Body by the vibrating Motion of the Parts of the Body, and gets beyond the reach of Attraction, being driven away with exceeding great Velocity.
Página 43 - ... (by which the rays cannot be brought into a focus upon the retina) they can discern in no other manner, than a sound eye can through a glass of broken jelly...
Página 44 - Before he was couched, he expected little advantage from seeing, worth undergoing an operation for, except reading and writing; for he said, he thought he could have no more pleasure in walking abroad than he had in the garden, which he could do safely and readily.
Página 44 - ... it; but his gratitude to his operator he could not conceal, never seeing him for some time without tears of joy in his eyes, and other marks of affection ; and if he did not happen to come at any time when he was expected, he would be so grieved, that he could not forbear crying at his disappointment.
Página 44 - A year after first seeing, being carried upon Epsom Downs, and observing a large prospect, he was exceedingly delighted with it, and called it a new kind of seeing.