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 5
... marked 12 on the scale of cir- cles , and a circle be described with the radius A B , D E will be the chord of ath part of the circumference , and will prick off a regular polygon of 12 sides in it . To reduce or enlarge the Area of a ...
... marked 12 on the scale of cir- cles , and a circle be described with the radius A B , D E will be the chord of ath part of the circumference , and will prick off a regular polygon of 12 sides in it . To reduce or enlarge the Area of a ...
Page 6
... marked 4 or 5 on the scale . To take the Square Root of a Number . - The line across the slider being set to the number upon the scale of plans , open the points A and B to take the number from any scale of equal parts ( see page 9 ) ...
... marked 4 or 5 on the scale . To take the Square Root of a Number . - The line across the slider being set to the number upon the scale of plans , open the points A and B to take the number from any scale of equal parts ( see page 9 ) ...
Page 11
... marked , 1 , the third , 2 , and so on , and we have the following General Rule . - To take off any number to three places of figures upon a diagonal scale . On the parallel indicated by the third figure , measure from the diagonal ...
... marked , 1 , the third , 2 , and so on , and we have the following General Rule . - To take off any number to three places of figures upon a diagonal scale . On the parallel indicated by the third figure , measure from the diagonal ...
Page 16
... marked 40 in the figure ( plate 1 , fig , 2 ) , the angle B A C will contain 41 ° . The Line of Rhumbs is a scale of the chords of the angles of deviation from the meridian denoted by the several points and quarter points of the compass ...
... marked 40 in the figure ( plate 1 , fig , 2 ) , the angle B A C will contain 41 ° . The Line of Rhumbs is a scale of the chords of the angles of deviation from the meridian denoted by the several points and quarter points of the compass ...
Page 17
... marked 2 , because N.N.E. is the second point of the compass from the north , and with one foot of the compasses on B describe an arc intersecting B C in C : join a C , and the angle B A C will represent the ship's course . On the other ...
... marked 2 , because N.N.E. is the second point of the compass from the north , and with one foot of the compasses on B describe an arc intersecting B C in C : join a C , and the angle B A C will represent the ship's course . On the other ...
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