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 2
... accuracy in the set of the compasses is required than can be effected by the joint alone , we have recourse to the use . Hair Compasses , in which the upper part of one of the steel points is formed into a bent spring , which , being ...
... accuracy in the set of the compasses is required than can be effected by the joint alone , we have recourse to the use . Hair Compasses , in which the upper part of one of the steel points is formed into a bent spring , which , being ...
Page 3
... accuracy than a pen- cil point ; but , in order to draw arcs or circles with ink or black lead , compasses with a moveable point are used . In the best description of these compasses the end of the shank is formed into a strong spring ...
... accuracy than a pen- cil point ; but , in order to draw arcs or circles with ink or black lead , compasses with a moveable point are used . In the best description of these compasses the end of the shank is formed into a strong spring ...
Page 8
... accuracy of such edges . This may be done by placing two such edges in contact and sliding them along each other , while held up between the eye and the light : if the edges fit close in some parts , so as to exclude the light , but ...
... accuracy of such edges . This may be done by placing two such edges in contact and sliding them along each other , while held up between the eye and the light : if the edges fit close in some parts , so as to exclude the light , but ...
Page 9
... accuracy of the deductions therefrom , will principally depend on the exactness with which the instruments are made and divided , and that those sciences will advance in proportion as these are less difficult in their use , and more ...
... accuracy of the deductions therefrom , will principally depend on the exactness with which the instruments are made and divided , and that those sciences will advance in proportion as these are less difficult in their use , and more ...
Page 13
... accuracy , and we have no check upon its errors ; while in the former the uniform manner in which the strokes of one scale separate from those of the other is some evidence of the truth of both * . * In Mr. Bird's celebrated scale , by ...
... accuracy , and we have no check upon its errors ; while in the former the uniform manner in which the strokes of one scale separate from those of the other is some evidence of the truth of both * . * In Mr. Bird's celebrated scale , by ...
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
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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...
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