Treatise on Mathematical Instruments: Their Construction, Adjustment, Testing and Use Concisely ExplainedVirtue Bros. & Company, 1866 - 185 pages |
From inside the book
Results 1-5 of 23
Page 9
... perfect in the performance of their respec tive operations . " * ON SCALES . Scales of equal parts are used for measuring straight lines , and laying down distances , each part answering for one foot , one yard , one chain , & c . , as ...
... perfect in the performance of their respec tive operations . " * ON SCALES . Scales of equal parts are used for measuring straight lines , and laying down distances , each part answering for one foot , one yard , one chain , & c . , as ...
Page 49
... perfect , the interval of the points GH will The survey of the metropolis is plotted to a scale of 60 inches to the mile . + For a description of the vernier , see preceding article . D measure on it the distance to which they were set ...
... perfect , the interval of the points GH will The survey of the metropolis is plotted to a scale of 60 inches to the mile . + For a description of the vernier , see preceding article . D measure on it the distance to which they were set ...
Page 88
... perfect . If a telescope is not good with its full aperture , its effect may be greatly improved , by putting a cover on the mouth , with a circular aperture , of about one - half the diameter that the tube has , in such a way that the ...
... perfect . If a telescope is not good with its full aperture , its effect may be greatly improved , by putting a cover on the mouth , with a circular aperture , of about one - half the diameter that the tube has , in such a way that the ...
Page 101
... perfect , and the clips which serve to confine the telescope in the Ys should be made fast . Lastly , to set the Axis of the Telescope perpendicular to the Vertical Axis round which the Instrument turns . - Place the telescope over two ...
... perfect , and the clips which serve to confine the telescope in the Ys should be made fast . Lastly , to set the Axis of the Telescope perpendicular to the Vertical Axis round which the Instrument turns . - Place the telescope over two ...
Page 102
... perfect . The object of the above adjustments is to make the line of collimation move round in a horizontal plane , when the in- strument is turned round its vertical axis , and the methods above explained suppose that the telescope ...
... perfect . The object of the above adjustments is to make the line of collimation move round in a horizontal plane , when the in- strument is turned round its vertical axis , and the methods above explained suppose that the telescope ...
Common terms and phrases
accuracy achromatic adjustment altitude axis azimuth beam compasses bisected breadth bubble called chromatic dispersion clamp coincide colatitude compasses construction correct cross wires described diaphragm distinct vision Ditto ditto divided drawing edge equal error extent will reach eye-piece feet figure fixed focal length given number goniometer graduated half horizontal inches index glass instru instrument intersection IVY LANE latitude lens lenses limb line of collimation line of numbers line of sines logarithmic means measured ment meridian microscope number of degrees object-glass observed paper parallax perpendicular placed plane position primary divisions prism protractor quarter girt radius rays reading reflected image reflector refracting refracting telescopes represent right angles right ascension round secants sector sextant side Slide Rule sliding speculum spherical aberration spirit level square staff station subdivisions tangents telescope theodolite transit transverse distance triangle tube turning 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 69 - ... that the sine of the angle of refraction bears a constant ratio to the sine of the angle of incidence...
Page 98 - ... 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 11 - 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 24 - 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 143 - ... 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*.