225 



of a millemetre of movement. The mirrors are burnished 

 loosely in their settings, which allows them to be turned round 

 to get rid of the multiple images. The weight of the instru- 

 ment in its case is 9|lbs. 



Mr. Ingpen said he did not often refer to anything which 

 Dr. Pigott did, but he certainly did achieve something in this 

 direction, for he had a tube cut down to 3in. and had some 

 sections of tube which fitted into it so that he got tube lengths 

 of 3in., 6in., 9in., 12in., and 15in. on a Powell stand. It would 

 be impossible to do this on many stands, but with a Powell it 

 was done quite easily. 



The President said he had a short and a long body which he 

 could exchange as desired. He liked this telescopic arrange- 

 ment of the tube with two draws and had found it per- 

 fectly satisfactory. He then read a note on a new optical 

 rule which he had designed, and exhibited the same to 

 the meeting and explained the way in which it was used. 



A vote of thanks to the President for his communication 

 was unanimously passed. 



Mr. Goodwin inquired if the President would tell them what 

 parts were measured to ascertain the tube length. 



The President, by means of a drawing on the black-board, 

 explained the difference between the mechanical and optical 

 tubo lengths. 



Mr. Karop said they were to have had a lantern exhibition 

 of photomicrographs by Mr. T. C. White, but he was un- 

 fortunately too unwell to be with them that evening as pro- 

 mised. 



Announcements of meetings for the ensuing month were then 

 made, special attention being called to the fact that at their 

 next ordinary meeting nominations to fill vacancies upon the 

 Committee would be asked for and an Auditor would have to 

 be elected. 



December 20th, 1895, 



Hydra viridis Mr. J. M. Allen. 



Euohlams lyra Mr. W. Burton. 



Journ. Q. M. C, Series II., No. 38. 16 



