Treatise on Mathematical Instruments: Their Construction, Adjustment, Testing and Use Concisely ExplainedVirtue Bros. & Company, 1866 - 185 pages |
From inside the book
Results 1-5 of 34
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 ...
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
Page 5 - To which is added, a description of the Principles and Practice of Isometrical Projection. By JF HEATHER, MA -With 14 Plates.
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...
Page 6 - Gd. 131. READY-RECKONER FOR MILLERS, FARMERS, AND MERCHANTS, showing the Value of any Quantity of Corn, with the Approximate Values of Mill-stones & Mill Work.
Page 11 - THE ENTIRE SERIES IS FREELY ILLUSTRATED ON WOOD AND STONE WHERE REQUISITE. The Public are respectfully informed that the whole of the late MB.
Page 5 - Gd. 55. NAVIGATION ; the Sailor's Sea Book : How to Keep the Log and Work it off, &c. ; Law of Storms, and Explanation of Terms, by J. Greenwood. 2s.
Page 24 - From the center at a draw the line ag for the axis of the gnomon agi, and from g let fall the perpendicular gi upon the horizontal meridian line an, and there will be formed a triangle ag i.
Page 143 - ... of them, those which apply to the eye-end of the telescope will answer much better ; the former having their errors magnified by the power of the telescope, will, in proportion to this power, and those errors, be less distinct than the latter. " In taking distances, when the position does not vary from the vertical above thirty or forty degrees, the handles which are attached to the circle are generally most conveniently used ; but in those which incline more to the horizontal, that handle which...
Page 3 - Denison. 3s. 6d. 78. STEAM AND LOCOMOTION, on the Principle of connecting Science with Practice, by J. Sewell. 2s. 78*.