On the Cork Equatorial Telescope, de. 351 
In the position sketched the reader points through the decli- 
nation axis to a prism at end r”, from this to another prism 7” 
(both of these prisms being attached to a plate hung out from 
upper end of polar axis), from r” the line of sight points to a 
prism 7” close to A circle 6, which is divided on its lower face. 
Though so many reflections take pace the reading at eye-piece 
of reader is most convenient and easy. 
This reading is available no matter what position of telescope 
be in A or declination. 
If the reader 77” be revolved through 90° on its own axis, the 
prism 7” at end points out through a hole in the tube, and by 
means of one single prism is available for reading the declination 
circle. 
If, now, the reader be again revolved 180° on its axis, that is 
to say, 90° from original position it points to, and is available for, 
reading the other vernier of declination circle, both verniers of 
which declination circle are illuminated by a lamp either on end 
of declination axis, or hanging some little distance out from centre 
of tube of telescope, as in the present instrument. 
New form of clamps for A and declination movement of 
equatorial telescopes. (Vide Figures 2 and 3.) 
The ordinary clamps in use for clamping the telescope axis 
to the clock or slow motion arrangements are considered highly 
unsatisfactory. They are generally more or less of the same form 
and character as the eccentric strap of a steam engine, that is to 
say, they consist of a metallic ring split in two pieces, and fit- 
ting on a grooved circular plate to which they can be rigidly 
clamped by tightening one or other of the screws, which hold 
the two half rings together, or round which they can be allowed 
to play freely, if the screws be left loose. 
The faults of this construction are :— 
Istly. That it requires several turns of the screw to affect 
the clamping. 
This is inconvenient and renders it impossible or very diffi- 
cult for the observer at the eye-end of telescope to affect the 
clamping in A. 
2ndly. That the action is such as most surely to disturb the 
direction of the telescope during the process of clamping. 
