A Treatise on Mathematical Instruments: Including Most of the Instruments Employed in Drawing, for Assisting the Vision, in Surveying and Levelling, in Practical Astronomy, and for Measuring the Angles of Crystals: in which Their Construction, and the Methods of Testing, Adjusting, and Using Them, are Concisley ExplainedJ. Weale, 1856 - 170 pages |
From inside the book
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Page 4
... inch radius , and fig . 2 to describe arcs of small radii with exactness by means of the adjusting screw C. For copying and reducing drawings , compasses of a pe- culiar construction are used ; the simplest form of which is that called ...
... inch radius , and fig . 2 to describe arcs of small radii with exactness by means of the adjusting screw C. For copying and reducing drawings , compasses of a pe- culiar construction are used ; the simplest form of which is that called ...
Page 10
... inches , 6 feet 7 inches for instance , extend the compasses from the primary division numbered 6 , to the 7th upper subdivision , reckoning back- wards , as before . Diagonal Scales . - In the simply - divided scales one of the primary ...
... inches , 6 feet 7 inches for instance , extend the compasses from the primary division numbered 6 , to the 7th upper subdivision , reckoning back- wards , as before . Diagonal Scales . - In the simply - divided scales one of the primary ...
Page 11
... inches in length . In one , the distances between the primary divisions are each half an inch , and in the other a quarter of an inch . The parallel next to the figures numbering these divisions must be considered the highest or first ...
... inches in length . In one , the distances between the primary divisions are each half an inch , and in the other a quarter of an inch . The parallel next to the figures numbering these divisions must be considered the highest or first ...
Page 12
... inch , and , consequently , the distances be- tween the subdivisions are each one - tenth of an inch , and the distances between the divisions of the vernier scale each one - tenth and one - hundredth of an inch . To take off the number ...
... inch , and , consequently , the distances be- tween the subdivisions are each one - tenth of an inch , and the distances between the divisions of the vernier scale each one - tenth and one - hundredth of an inch . To take off the number ...
Page 14
... inches are divided into tenths , as in the scale described in the text , and 100 of these tenths are divided into 100 parts for the vernier scale . * We give the constructions in the text to show the nature of the scales ; but in ...
... inches are divided into tenths , as in the scale described in the text , and 100 of these tenths are divided into 100 parts for the vernier scale . * We give the constructions in the text to show the nature of the scales ; but in ...
Other editions - View all
A Treatise On Mathematical Instruments: Including Most of the Instruments ... John Fry Heather No preview available - 2022 |
A Treatise on Mathematical Instruments: Including Most of the Instruments ... John F Heather No preview available - 2016 |
Common terms and phrases
accuracy adjustment altitude axis azimuth beam compasses bisected breadth bubble called chain chromatic dispersion clamp coincide colatitude compasses construction correction cross wires described diaphragm distinct vision Ditto ditto divided drawing edge equal error extent will reach eye-piece feet figure focal length given number goniometer horizontal inches index glass instru instrument intersection latitude lens lenses limb line of chords line of collimation line of numbers line of sines logarithmic marked means measured meridian microscope number of degrees object object-glass observed paper parallax parallel plate pass perpendicular placed plane position primary divisions prism protractor quarter girt radius rays reading reflected image reflector refracting refracting telescopes represent right ascension round secants sector sextant side sixth column slider sliding speculum spherical aberration spirit level square station strument subdivisions tangents telescope theodolite transverse distance triangle tube turning vernier scale vertical circle zero