A Treatise of Mathematical Instruments, including most of the instruments employed in Drawing; for assisting the vision; in Surveying and Levelling, in practical Astronomy and for measuring the Angles of CrystalsJohn Weale, 1849 - 183 pages |
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Page 83
John Fry HEATHER. The magnifying power of any refracting microscope or tele- scope may be practically found , by ... telescope or microscope . In all microscopes it is necessary to illuminate the object strongly , in consequence both ...
John Fry HEATHER. The magnifying power of any refracting microscope or tele- scope may be practically found , by ... telescope or microscope . In all microscopes it is necessary to illuminate the object strongly , in consequence both ...
Page 84
... TELESCOPES . The Refracting Telescope consists of a convex object - glass , which forms an image of a distant object , and an eye - piece of one or more lenses , which performs the office of a micro- scope for viewing this image . The ...
... TELESCOPES . The Refracting Telescope consists of a convex object - glass , which forms an image of a distant object , and an eye - piece of one or more lenses , which performs the office of a micro- scope for viewing this image . The ...
Page 85
... refracting media ; and hence it is always an object to employ as few lenses as possible , consistently with the attainment of the other requisites of a good tele- scope . Refracting telescopes for astronomical observations are now ...
... refracting media ; and hence it is always an object to employ as few lenses as possible , consistently with the attainment of the other requisites of a good tele- scope . Refracting telescopes for astronomical observations are now ...
Page 87
... telescope a concave eye - lens of the same focal length , a simple telescope ... refracting tele- scopes are theoretically unlimited ; but the difficulty of ... refracting telescopes . By the substitution , however , of re- flectors ...
... telescope a concave eye - lens of the same focal length , a simple telescope ... refracting tele- scopes are theoretically unlimited ; but the difficulty of ... refracting telescopes . By the substitution , however , of re- flectors ...
Page 89
... telescope is also shorter than the Gregorian . It is , however , inferior to the Newtonian tele- scope for celestial observations , and not well adapted for ter- restrial purposes on account of the inversion of ... REFRACTING TELESCOPES . 89.
... telescope is also shorter than the Gregorian . It is , however , inferior to the Newtonian tele- scope for celestial observations , and not well adapted for ter- restrial purposes on account of the inversion of ... REFRACTING TELESCOPES . 89.
Other editions - View all
A Treatise On Mathematical Instruments: Including Most of the Instruments ... John Fry Heather No preview available - 2018 |
A Treatise on Mathematical Instruments: Including Most of the Instruments ... John Fry Heather No preview available - 2015 |
A Treatise on Mathematical Instruments: Including Most of the Instruments ... John Fry Heather No preview available - 2016 |
Common terms and phrases
accuracy achromatic adjustment altitude axis azimuth beam compasses bisected breadth bubble called chain chromatic dispersion clamp coincide colatitude compasses construction correction cross wires described diaphragm distinct vision divided drawing edge extent will reach eye-piece feet figure focal length given number graduated Gunter's chain half horizontal inches index glass instru instrument intersection latitude lens lenses limb line of chords line of collimation line of numbers line of sines logarithmic marked means measured ment meridian microscope number of degrees object object-glass observed paper parallax pass pencil of light perpendicular placed plane position primary divisions prism protractor quarter girt radius rays reading reflected image reflector refracting Refracting Telescope represent right ascension round secants sector sextant side slider sliding speculum spherical aberration spirit level square station strument subdivisions taken tangents telescope theodolite tion transverse distance tube turning vernier plate vernier scale vertical circle zero