359 



and would give altogether 36 changes. The chief point to be 

 noted in order to ensure success was to have the central colour 

 very dark and the margin very light. 



Mr. Rheinberg said he had found a very simple way of ob- 

 taining one colour was to have a ring of black between the two 

 colours. This ensured a ground of one colour only. 



A vote of thanks to Mr. Karop and those who had spoken on 

 the subject was passed on the motion of the President. 



Mr. Goodwin exhibited and described the perfected form of 

 his small microscope lamp, which had been improved in various 

 ways since last brought before the Club. He still used the 

 paper wick, but found it ensured a more regular supply of oil 

 to have this attached to some cotton in a glass tube passing to 

 the bottom of the reservoir ; this entirely obviated the incon- 

 venience of too much oil rising and flowing over. 



Mr. E. M. Nelson said he had seen many lamps which had 

 been brought out from time to time, but had discarded the 

 small ones because they were imperfectly made, and they all 

 leaked. He thought, however, that a good small lamp for ex- 

 hibition work was much wanted. The one which Mr. Goodwin 

 had shown them was very nicely made, and it was quite equal 

 to those requirements ; the blotting-paper wick was a very 

 good idea, and he certainly thought Mr. Goodwin had " scored 

 one." 



Mr. Karop said that next to the capabilities of a lamp the 

 thing of most importance about it was to know what was its 

 commercial value. Could Mr. Goodwin tell them about what 

 it would be likely to cost ? 



Mr. Goodwin believed that it would be sold at about 10s., or 

 if made with the best glass, about 2s. more. 



Mr. Karop said the blotting-paper wick was very ingenious, 

 but he believed there was one to be had which never required 

 attention, either cutting or cleaning. It was called the simplex 

 wick, and was used by cyclists. He thought the suggestion 

 might be worth trying. 



The thanks of the Club were voted to Mr. Goodwin for his 

 communication. 



Mr. E. M. Nelson made some further remarks upon drawings 

 made from the microscope with a camera lucida, showing by 

 means of diagrams on the board how the distortion towards the 



