352 Scientific Proceedings, Royal Dublin Society. 
The new construction consists of a metallic ring of a V 
section, fitting into a correspording groove in the plate to which 
it is required to be clamped (see Figure 3), and the clamping 
is affected by the forcing of a V shaped tooth (V) into the groove 
by the screw and lever (SS), to which lever cords are attached 
by which the observer at eye-end of telescope has complete 
control of the apparatus. In this new clamp + of a turn clamps 
or unclamps the instrument, and the action being radial no 
shifting of the instrument can take place. 
Fig. 2. 
