A Treatise on the KaleidoscopeArchibald Constable & Company, 1819 - 166 էջ |
From inside the book
Արդյունքներ 9–ի 1-ից 5-ը:
Էջ 41
... vision , the field of view , and consequently every pattern which it con- tains , must be distorted , and destitute of beauty , from this cause alone . Hitherto we have alluded only to symmetry of form , but it is manifest that , before ...
... vision , the field of view , and consequently every pattern which it con- tains , must be distorted , and destitute of beauty , from this cause alone . Hitherto we have alluded only to symmetry of form , but it is manifest that , before ...
Էջ 44
... field enclosing an eccentric circular pattern . Such a position of the object is therefore entirely unfit for the production of a symmetrical picture , unless the object should be such as wholly to exclude the view of the cir- cular field ...
... field enclosing an eccentric circular pattern . Such a position of the object is therefore entirely unfit for the production of a symmetrical picture , unless the object should be such as wholly to exclude the view of the cir- cular field ...
Էջ 45
... field of view . Hence we may conclude , that a per- fectly symmetrical pattern cannot be exhibited in the circular field of view , when the object is placed between O and E , or any where within the reflec- tors . If the eye could be ...
... field of view . Hence we may conclude , that a per- fectly symmetrical pattern cannot be exhibited in the circular field of view , when the object is placed between O and E , or any where within the reflec- tors . If the eye could be ...
Էջ 53
... angle from a verti- cal plane parallel to M N. Let us now . consider what will take place by a variation in the length of the reflecting planes , the angular extent of the field of view remaining always the same . If AOE , AOE , Fig ...
... angle from a verti- cal plane parallel to M N. Let us now . consider what will take place by a variation in the length of the reflecting planes , the angular extent of the field of view remaining always the same . If AOE , AOE , Fig ...
Էջ 54
... field of the shorter instrument , will have less intensity of light than a similarly situated point in a larger in- strument . But in this case , the field of view in the short instrument is proportionally enlarged , so that the ...
... field of the shorter instrument , will have less intensity of light than a similarly situated point in a larger in- strument . But in this case , the field of view in the short instrument is proportionally enlarged , so that the ...
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Common terms and phrases
angle A O B angles of 90 angles of incidence angular aperture angular point aperture apparent magnitude applied beauty brass rim Camera Obscura catoptric centre CHAP circle circular field coloured glass combination composed constructed convex lens DEUTSCHES MUSEUM direct vision distance effects produced equal exhibited eye end field of view figure fixed flectors focal length fragments half Hence images formed inches inclination Indigo instru instrument intensity inverted image ject Kaleido last reflected last sector leidoscope lens light looking-glass manner ment mirror BO motion move number of reflections number of sectors object plate optical ornaments pattern pieces plane mirrors Polyangular polygon position principles rays rectilineal reflected images reflectors at angles regular polygon ring RR round scholium screws seen by direct semitones shewn in Fig shews side specula speculum speculum metal square stationary surface symmetrical picture symmetrically related three reflectors tion transparent triangle tube velocity