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Mr. Sidebotham also exhibited a new finder for high 
powers. It consists of squares formed by crossing lines, one 
hundredth of an inch apart, enclosing progressive numbers, 
executed by photography. He promised to prepare a number 
for the use of the members, all to be exactly alike 
Mr. Joy exhibited a nose-piece, made for him nearly two 
years ago, consisting of a diaphragm plate, under which are 
screwed four objectives of different poAvers ; the centreing is 
so true, that he can use the three-inch as a finder for the j or 
even |-inch poAver. Several members of the Section have 
nose-pieces made upon the same principle. 
Mr. Linton and Mr. Watson exhibited the tuft scales on 
the upper wing of the Peronea Cristana and others. 
