Treatise on Mathematical Instruments: Their Construction, Adjustment, Testing and Use Concisely ExplainedVirtue Bros. & Company, 1866 - 185 pages |
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Page 4
... called bow compasses . with a permanent ink or pencil point , are used . They are formed with a round head , which rolls with ease between the fingers . The adjoining figures represent two varieties of bow pen , fig . 1 being well ...
... called bow compasses . with a permanent ink or pencil point , are used . They are formed with a round head , which rolls with ease between the fingers . The adjoining figures represent two varieties of bow pen , fig . 1 being well ...
Page 8
... 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 divisions from the plotting scale and protractor ( p . 33 ) . This ...
... 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 divisions from the plotting scale and protractor ( p . 33 ) . This ...
Page 9
... called a scale of 30 , when 30 of these small parts are equal to one inch . If , then , these subdivisions be taken as units , each to represent one mile , for instance , or one chain , or one foot , & c . , the primary divisions will ...
... called a scale of 30 , when 30 of these small parts are equal to one inch . If , then , these subdivisions be taken as units , each to represent one mile , for instance , or one chain , or one foot , & c . , the primary divisions will ...
Page 12
... called , one division of the vernier scale , exceeds one of the subdivisions by a tenth part of a subdivision , or a hundredth part of a primary division . In our figure the distances between the primary divisions are each one inch ...
... called , one division of the vernier scale , exceeds one of the subdivisions by a tenth part of a subdivision , or a hundredth part of a primary division . In our figure the distances between the primary divisions are each one inch ...
Page 17
... called the primitive , and the circumference of a circle , de- scribed with a radius , representing , upon the reduced scale of the drawing , the radius of the sphere , is called the circum ference of the primitive . Lines , drawn from ...
... called the primitive , and the circumference of a circle , de- scribed with a radius , representing , upon the reduced scale of the drawing , the radius of the sphere , is called the circum ference of the primitive . Lines , drawn from ...
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Treatise on Mathematical Instruments: Their Construction, Adjustment ... John Fry Heather No preview available - 2016 |
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
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