Verniers sentence example
- Measures 1 The circles by Reichenbach, then almost exclusively used in Germany, were read by verniers only.
- The word is used also to designate the supporting frame or arms carrying the microscopes or verniers of a graduated circle.
- Repsold introduced essential improvements in the meridian circles by substituting microscopes (on Jesse Ramsden's plan) for the verniers to read the circles, and by making the various parts perfectly symmetrical.
- The two verniers on the azimuth circle having been read, the magnet is then inverted, i.e.
- The mean of all the readings of the verniers gives the reading on the azimuth circle corresponding to the magnetic meridian.Advertisement
- Hence if the readings of the verniers on the azimuth circle are made when the transit is observed we can deduce the reading corresponding to the geographical meridian.
- The verniers having been read, the cross-arm is rotated so as to deflect the needle a in the opposite direction, and a new setting is taken.
- A collar is provided, which when tightened on the vertical axis, otherwise free to move, holds it rigidly in position with respect to the plate PP. To this collar is attached a slow-motion screw, working against a reaction spring, by which the plate rr can be rotated through a small arc. The upper plate carrying two, three .or four verniers vv is attached to a vertical coned pillar passing through the centre of the larger pillar and rotating in it; this plate can be clamped to the lower plate by means of the screw C, and can be rotated with respect to it by the slow-motion screw d.
- The verniers are attached to arms uu bearing on an enlargement of one trunnion of the telescope, one arm pro j ecting downwards and embracing a projection on the standard t.
- To the same frame is attached a bubble, which should be parallel with the centre line of the verniers.Advertisement
- On the side of the telescope opposite to the horizontal axis is attached a graduated circle g, and, turning concentrically with this circle, is a framework h, to which the readers and verniers of the circle are fixed.
- In practice the vertical circle is adjusted once for all, so that when the levels k and l are in the centre of their run, the verniers read true zenith distances.
- Assuming, for example, that the northern star has the smaller right ascension, the instrument is first, with the aid of the stop, placed in the meridian towards the north; the verniers of the graduated circle g are set to read to the reading 40-2(Sn+Ss) where 0 is the approximate latitude of the place and Sn, Ss the declinations of the northern and southern star respectively; then the level frame h is turned till the levels k and I are in the middle of their run, and there clamped by the screw m, aided in the final adjustment by the adjoining slow motion screw shown in the figure.
- These verniers can be read to and estimated to O' 2.
- Now, if a graduated circle B B is attached to the declination axis, together with the necessary verniers or microscopes V V for reading it (see Transit Circle), so arranged that when the telescope is turned on the declination axis till its optical axis is parallel to A A the vernier reads 0Ã‚° and when at right angles to A A 90Ã‚°, then we can employ the readings of 2 Herschel, Phil.Advertisement
- In this instrument a considerable linear relative movement of the divided lens corresponds with a comparatively small separation of the double image, so that simple verniers reading to 6 1 0 in.