Treatise on Mathematical Instruments: Their Construction, Adjustment, Testing and Use Concisely ExplainedVirtue Bros. & Company, 1866 - 185 pages |
Common terms and phrases
accuracy adjustment altitude arc of excess azimuth beam compasses bisected bubble called chain clamp coincide colatitude columns compasses construction correct cross wires described diaphragm difference Ditto ditto divided drawing edge equal extent will reach eye-piece feet figure fixed focal length gnomonic projection goniometer graduated Gunter's chain half horizon glass inches index error index glass instru intersection latitude lens lenses light line of chords line of collimation line of sines logarithmic MATHEMATICAL INSTRUMENTS means measured ment meridian microscope moved object-glass observed parallax pencil perpendicular plane plot position primary divisions prism protractor radius rays reading reflected image reflector Refracting telescopes refraction represent right angles right ascension round sextant side sixth column spherical aberration spirit level square staff station strument subdivisions survey tangent tangent screw telescope theodolite transit transverse distance tube turning vernier plate vernier scale vertical circle zero
Popular passages
Page 5 - To which is added, a description of the Principles and Practice of Isometrical Projection. By JF HEATHER, MA -With 14 Plates.
Page 59 - ... that the sine of the angle of refraction bears a constant ratio to the sine of the angle of incidence...
Page 86 - ... of this field of view. We must therefore place some fixed point in the field, of view, and in the focus of the eye-piece, and the point to which the measurement will have reference will be that point of the object viewed, which...
Page 6 - Gd. 131. READY-RECKONER FOR MILLERS, FARMERS, AND MERCHANTS, showing the Value of any Quantity of Corn, with the Approximate Values of Mill-stones & Mill Work.
Page 185 - THE ENTIRE SERIES IS FREELY ILLUSTRATED ON WOOD AND STONE WHERE REQUISITE. The Public are respectfully informed that the whole of the late MB.
Page 5 - Gd. 55. NAVIGATION ; the Sailor's Sea Book : How to Keep the Log and Work it off, &c. ; Law of Storms, and Explanation of Terms, by J. Greenwood. 2s.
Page 14 - From the center at a draw the line ag for the axis of the gnomon agi, and from g let fall the perpendicular gi upon the horizontal meridian line an, and there will be formed a triangle ag i.
Page 131 - ... of them, those which apply to the eye-end of the telescope will answer much better ; the former having their errors magnified by the power of the telescope, will, in proportion to this power, and those errors, be less distinct than the latter. " In taking distances, when the position does not vary from the vertical above thirty or forty degrees, the handles which are attached to the circle are generally most conveniently used ; but in those which incline more to the horizontal, that handle which...
Page 3 - Denison. 3s. 6d. 78. STEAM AND LOCOMOTION, on the Principle of connecting Science with Practice, by J. Sewell. 2s. 78*.