Pike's Illustrated Descriptive Catalogue of Optical, Mathematical and Philosophical Instruments: Manufactured, Imported, and Sold by the Author; with the Prices Affixed at which They are Offered in 1848 ...The author, 1848 |
Other editions - View all
Pike's Illustrated Descriptive Catalogue of Optical, Mathematical and ... Benjamin Pike (Jr ) No preview available - 2016 |
Pike's Illustrated Descriptive Catalogue of Optical, Mathematical and ... Benjamin Pike No preview available - 2016 |
Pike's Illustrated Descriptive Catalogue of Optical, Mathematical and ... Benjamin Pike No preview available - 2016 |
Common terms and phrases
294 BROADWAY adjustment air pump altitude angle apparatus artificial horizon attached axis barrel battery bottom brass ball brass cap centre centre of gravity centrifugal force circle compass connected consists cushion cylinder degrees distance divided earth ecliptic electrical machine electrometer equal fastened fixed fluid force frame German silver glass pillar glass tube globe gnomon half handle hole horizontal inches inches in diameter inches long instrument lever Leyden jar limb lower mahogany mercury meridian metal moon motion mounted movable moving object observation ounces pair parallel pass piece piston placed plane plate pole position Price prime conductor protractor pulley quadrant receiver represents revolve round scale screw sextant side silk sliding socket space described sphere spirit level square stop-cock supported surface telescope theodolite tion tricity turned upper valve velocity vernier vertical vessel weight wheel wire zinc
Popular passages
Page 229 - The advantage of this is, that by a partial revolution of the two troughs, thus united, upon pivots which support them at the ends, any fluid which may be in one trough must flow into the other, and, reversing the movement, must flow back again. The galvanic series being placed in one of the troughs...
Page 71 - ... well as any other; for the rays incident on the index-glass will pass through the transparent half of the horizonglass, without much diminution of their brightness. " The advantages of this instrument, when compared with the sextant, are chiefly these : the observations for finding the indexerror are rendered useless, all knowledge of that being put out of the question, by observing both forwards and backwards. By the same means the errors of the...
Page 228 - A voltaic series fixed in a trough is combined with another trough destitute of plates, and of a capacity sufficient to hold all the acid necessary for an ample charge. The trough containing the series is joined to the other lengthwise, edge to edge ; so that, when the sides of the one are vertical, those of the other must be horizontal. The advantage of...
Page 103 - ... half the error, in the same manner, must be gone through again, until, by successive approximations, the object is found to be bisected in both positions of the axis ; the adjustment will then be perfect. The collimation adjustment may likewise be examined from time to time, by observing the transit of Polaris, or any other close circumpolar star, over the first three wires, which gives the intervals in time from the first to the second, and from the first to the third wire ; and then reversing...
Page 77 - The Adjustments. The first adjustment is that of the line of collimation, — that is, to make the intersection of the cross wires coincide with the axis of the cylindrical rings on which the telescope turns : it is known to be correct, when an eye looking through the telescope observes their intersection continue on the same point of a distant object during an entire revolution of the telescope. The usual method of making this adjustment is as follows...
Page 70 - The foregoing instructions for taking distances apply equally for taking altitudes by the sea or artificial horizon, they being no more than distances taken in a vertical plane. Meridian altitudes cannot, however, be taken both backwards and forwards the same day, because there is not time ; all, therefore, that can be done is, to observe the altitude one way, and use the index error ; but, even here, you have a mean of that altitude, and this error taken on three different sextants. Both at sea...
Page 239 - A plate of amalgamated zinc, D, varying with the fancy of the operator from one half to the entire width of the silver is placed on each side of the wood. This is set into a glass vessel...
Page 69 - Prepare the instrument for observation by screwing the telescope into its place, adjusting the drawer to focus, and the wires parallel to the plane, exactly as you do with a sextant : also set the index forwards to the rough distance of the sun and moon, or moon and star; and, holding the circle by the short handle, direct the telescope to the fainter object, and make the contact in the usual way. Now read off the degree, minute, and second, by that branch of the index to which the...
Page 231 - Fig. 1, there is an interstice between the mass of tin connecting the ten copper sheets, and that connecting the ten zinc sheets. The screw forceps, appertaining to each of the tin masses, may be seen on either side of the interstice: and likewise a wire for ignition held between them.
Page 77 - ... any deviation in it is easily rectified, by releasing the screws by which it is held, and tightening them again after having made the adjustment ; or, what is perhaps better, note the quantity of deviation as an index error, and apply it, plus or minus, to each vertical angle observed. This deviation is best determined by repeating the observation of an altitude or depression in the reversed positions, both of the telescope and the vernier plate: the two readings will have equal and opposite...