662 PROCEEDINGS OF THE SOCIETY. 



arrangement made with a tripod on which the instrument was placed. 

 For drawing he had a small table at the level of the stage mounted 

 on a swivel, so that it could be used at any angle. He never worked 

 below the level of the stage. 



Mr. Michael said he had used the camera lucida a great deal in 

 making drawings of all kinds, and his reason for rising was that it 

 seemed to be taken for granted that Zeiss's form of camera was not 

 so good as others. So far as his own experience and work were con- 

 cerned, he had found it to be about the best, and he must confess 

 that he did not see the image of the brasswork as had been described. 

 His plan was very simple, for he used a drawing-board propped up 

 upon books, so that the board was practically a continuation of the 

 stage of the Microscope. If he thought that the image was not true 

 he put in a stage micrometer and drew the image of it, and if this 

 was done in two directions and both drawings were alike he knew 

 that the projection was correct. As to the difficulty of seeing the 

 pencil, he found that this varied very much with different persons, 

 and that when he could not see it, others could do so with perfect 

 distinctness. He liked to work with two lights and to have the light 

 on the drawing-board much brighter than that in the Microscope ; 

 but on the other hand he found there were many persons who under 

 these conditions would find that the image of the pencil overpowered 

 the light from the object. He certainly thought the Zeiss form the 

 best for ordinary mounted objects and for all such as were not 

 mounted in fluid, whilst if it was desired to draw an object mounted 

 in fluid there was' nothing better for the purpose than the Nachet 

 form. The camera lucida, it should always be remembered, was an 

 instrument for drawing outlines rather than filling up details. 



Mr. Beck said that the difficulties arising in connection with the 

 camera lucida had from time to time come pretty prominently before 

 him. There were two central forms which might be taken as types ; 

 one of these was the neutral tint reflector, and the other was the 

 Wollaston. The neutral tint glass inverted the image so that a 

 drawing made by it of anything which had the heart on the right 

 side would be drawn as if it was on the left side. The practical 

 difficulty met with in the use of the Wollaston camera was not 

 because the Microscope had to be used in a horizontal position, but 

 because of the difficulty experienced by some persons of seeing the 

 point of the pencil. This might arise from the fact that very 

 freq[uently persons used a large amount of light so that the pupil of 

 the eye was very much contracted. He thought nothing could be 

 better than the old Wollaston form ; he had never himself found any 

 difficulty in using it, and in spite of all the new contrivances which 

 had been brought out, a large number of persons still used it and 

 preferred it. 



Mr. James Smith said that with regard to the difficulty which 

 Mr. Beck had stated some people experienced in seeing the point of 

 the pencil, the best plan was to cut a very fine point to the pencil, 

 and then dip it into black ink, which would render it perfectly plain 

 on the white paper. With regard to the adjustment of light, it would 



