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 68
Page 49
... object to be attained , in the use of this instrument , is the nice adjustment of the points G , H , to any definite distance apart . This is accomplished by two verniert or reading plates , b , c , each fixed at the side of an opening ...
... object to be attained , in the use of this instrument , is the nice adjustment of the points G , H , to any definite distance apart . This is accomplished by two verniert or reading plates , b , c , each fixed at the side of an opening ...
Page 52
... object were to enlarge the drawing to double its scale , then the tracer must be placed upon the arm D F , and the pencil at c ; and , if a copy were required of the same scale as the original , then , the sliding indices still ...
... object were to enlarge the drawing to double its scale , then the tracer must be placed upon the arm D F , and the pencil at c ; and , if a copy were required of the same scale as the original , then , the sliding indices still ...
Page 67
... object will be to consider the construction , and principles of action , of such instruments as are indispensable to assist the vision in making observations upon distant objects , whether upon terrestrial objects for the purposes of ...
... object will be to consider the construction , and principles of action , of such instruments as are indispensable to assist the vision in making observations upon distant objects , whether upon terrestrial objects for the purposes of ...
Page 68
... object is viewed through a prism , the two following effects P are produced . S 1stly . The ap- parent position of K M the object is changed , so that , if the prism be held with its edge -L downwards , as in the accompanying figure ...
... object is viewed through a prism , the two following effects P are produced . S 1stly . The ap- parent position of K M the object is changed , so that , if the prism be held with its edge -L downwards , as in the accompanying figure ...
Page 69
... object is observed , in order to make the apparent place of this object , as viewed through the prism , coincide with the actual place of other objects seen directly , as in the prismatic compass † , or for the mere pur- pose of ...
... object is observed , in order to make the apparent place of this object , as viewed through the prism , coincide with the actual place of other objects seen directly , as in the prismatic compass † , or for the mere pur- pose of ...
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...
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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...
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