Treatise on Mathematical Instruments: Their Construction, Adjustment, Testing and Use Concisely ExplainedVirtue Bros. & Company, 1866 - 185 pages |
From inside the book
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Page 42
... ment of the degrees at which it becomes a transverse distance will be the number of degrees required . For a secant make the given line a transverse distance at 90 on the sines ; then the extent of the radius will be a trans- verse ...
... ment of the degrees at which it becomes a transverse distance will be the number of degrees required . For a secant make the given line a transverse distance at 90 on the sines ; then the extent of the radius will be a trans- verse ...
Page 47
... ment indicated would be something between 22 ° 40 ′ and 23 ° , which the observer , should there be no other mechanism at- tached to the vernier , must estimate by guess , according to the best of his judgment . By the aid , however ...
... ment indicated would be something between 22 ° 40 ′ and 23 ° , which the observer , should there be no other mechanism at- tached to the vernier , must estimate by guess , according to the best of his judgment . By the aid , however ...
Page 52
... ment of the same object . In fact , while the pantagraph affords the most rapid means of reducing a drawing , we cannot re- commend its use for enlarging a copy , or even for copying upon the same scale . To produce a Copy of the same ...
... ment of the same object . In fact , while the pantagraph affords the most rapid means of reducing a drawing , we cannot re- commend its use for enlarging a copy , or even for copying upon the same scale . To produce a Copy of the same ...
Page 55
... ment most commonly used for taking the dimensions and finding the contents of timber . It consists of a rule one foot long , having on its face a groove throughout its entire length , in which a second rule of the same length slides ...
... ment most commonly used for taking the dimensions and finding the contents of timber . It consists of a rule one foot long , having on its face a groove throughout its entire length , in which a second rule of the same length slides ...
Page 92
... ment , and all the principal lines , and the distances of the extreme points , are calculated from triangles connecting them with this base . An instrument which has been known to answer well for this purpose is a steel chain 100 feet ...
... ment , and all the principal lines , and the distances of the extreme points , are calculated from triangles connecting them with this base . An instrument which has been known to answer well for this purpose is a steel chain 100 feet ...
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*.