By Mr. Howarp Grubs, F.R.AS. 3 
With this oven the author considers that it would be possible 
to anneal discs of very large size. 
The general conclusions arrived at by the author are, “ That 
no one kind of telescope is the best possible for all kinds of 
work,” and in choosing the best form of telescope reference must 
be had to the uses for which the telescope is intended, its 
position, surroundings, &c. 
The author speaks also of experiments that are being made, 
which, if successful, will increase the reflective power of metallic 
mirrors by 25%, and add considerably to the balance of their 
advantages. 
In discussing the most suitable mounting for such monster 
instruments the author suggests that all the laborious operations 
connected with the working of the equatorial should be effected 
by hydraulic power, so as to relieve the observer from any excess 
of manual labour or dependence on subordinates. 
VOL. L—PART I. B2 
