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
... screw . A groove is formed in the shank , which receives the spring when screwed up tight ; and , by turning the screw backwards , the steel point may be gradu- ally allowed to be pulled backwards by the spring , and may again be gradu ...
... screw . A groove is formed in the shank , which receives the spring when screwed up tight ; and , by turning the screw backwards , the steel point may be gradu- ally allowed to be pulled backwards by the spring , and may again be gradu ...
Page 3
... screw . COMPASSES WITH MOVEABLE POINTS . If an arc or circle is to be described faintly , merely as a guide for the terminating points of other lines , the steel points are generally sufficient for the purpose , and are suscep- tible of ...
... screw . COMPASSES WITH MOVEABLE POINTS . If an arc or circle is to be described faintly , merely as a guide for the terminating points of other lines , the steel points are generally sufficient for the purpose , and are suscep- tible of ...
Page 4
... screw C. For copying and reducing drawings , compasses of a pe- culiar construction are used ; the simplest form of which is that called wholes and halves , because the longer legs being twice the length Fig 2 с B Fig 1 A of the shorter ...
... screw C. For copying and reducing drawings , compasses of a pe- culiar construction are used ; the simplest form of which is that called wholes and halves , because the longer legs being twice the length Fig 2 с B Fig 1 A of the shorter ...
Page 7
... screw , so as to draw lines of any required fineness or thick- ness . One of the blades is framed with a joint , so that by taking out the screw the blades may be completely opened , and the points effectively cleaned after use . The ...
... screw , so as to draw lines of any required fineness or thick- ness . One of the blades is framed with a joint , so that by taking out the screw the blades may be completely opened , and the points effectively cleaned after use . The ...
Page 8
... screw to set the pen to any required small distance . This is usually called the road pen . The best pricking point is a fine needle held in a pair of forceps ( fig . 3 ) . It is used to mark the intersec- tions of lines , or to set off ...
... screw to set the pen to any required small distance . This is usually called the road pen . The best pricking point is a fine needle held in a pair of forceps ( fig . 3 ) . It is used to mark the intersec- tions of lines , or to set off ...
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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