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 10
Page 60
... column 3 may be found by dividing the approximate contents by the denomination of the fractions . ( Problem 2. ) If the excess of the breadth over the thickness be compared with the quarter girt , the correction has to the approximate ...
... column 3 may be found by dividing the approximate contents by the denomination of the fractions . ( Problem 2. ) If the excess of the breadth over the thickness be compared with the quarter girt , the correction has to the approximate ...
Page 107
... columns the readings of the staff at the back stations and fore stations respectively , and the difference of the sums of these readings * The error of refraction is that arising from the bending of the rays of light during their ...
... columns the readings of the staff at the back stations and fore stations respectively , and the difference of the sums of these readings * The error of refraction is that arising from the bending of the rays of light during their ...
Page 109
... column are entered the distances between the several stations , which , being successively added to the pre- ceding total , give the total distances of each station from the starting point : in the next column are entered the distances ...
... column are entered the distances between the several stations , which , being successively added to the pre- ceding total , give the total distances of each station from the starting point : in the next column are entered the distances ...
Page 110
... columns are entered the readings of the staves ; and in the sixth column the heights above datum of the several stations are computed by adding the back reading to the height last found , and subtracting the fore reading from the sum ...
... columns are entered the readings of the staves ; and in the sixth column the heights above datum of the several stations are computed by adding the back reading to the height last found , and subtracting the fore reading from the sum ...
Page 111
... column ; but , the distances between them being entered successively in the first column , their respective distances from the instrument may at any time be determined , if required . The height of the in strument itself may be entered ...
... column ; but , the distances between them being entered successively in the first column , their respective distances from the instrument may at any time be determined , if required . The height of the in strument itself may be entered ...
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*.