334 



asked Mr. Swift to make him one on Nachet's principle, and hoped for 

 success in using it. He was very glad that the subject had been brought 

 before them, and hoped that a good many of the members would have some- 

 thing to say upon it. 



Dr. M. C. Cooke thought he might challenge the members that he made 

 more microscopical drawings with the camera lucida than any one present. 

 Scarcely a day passed without his making at least 20 of them, and he 

 might say that he made from 100 to 1,000 every week. He believed he was 

 the first to bring into notice the Nachet prism ; he bought one many years 

 ago with an old microscope, and found it answer exceedingly well. He was 

 in the habit of using a tripod microscope, which had the advantage of stand- 

 ing always at the same angle, and he kept the prism always upon the eye- 

 piece, so that he could use it at any moment. When he first commenced to 

 use it, he measured very carefully the number of diameters that the draw- 

 ing was magnified, so that he could always tell exactly the diameter or size 

 of any object by means of a paper scale made for the purpose, all objects 

 being drawn at the same angle and the same distance, and with the same 

 eyepiece and objective. He had found this method of measurement far 

 superior to all others, because of the facility with which it was done. He 

 frequently made 40 or 50 drawings in an evenmg in this way, which would 

 1 be quite impossible if he had to mount and adjust a camera lucida every 

 time. 



Mr. Hailes said he was sorry he M'as not aware that the subject under dis- 

 cussion was going to be brought forward, or he would have brought up a 

 form of camera lucida to the meeting, which was not amongst those figured. 

 It was made by Amici, and bore his name and mark. It consisted of a brass 

 box with one end closed by a perfectly parallel piece of plate glass, having 

 a prism in front of it. It had all the advantage of " the Beale," without 

 the reversal of the image, which was of great importance in drawing such 

 things as Foraminifera, in which one might draw the shell coiled the wrong 

 way. He would bring up this apparatus to the next meeting. 



Mr. Curties said it was a known fact that some of the most correct 

 drawings that had been made were drawn without a camera lucida, and that 

 in most of the schools students were taught to draw without. 



Dr. Matthews suggested that, as the subject had proved so interesting, 

 its farther discussion should be continued at their next meeting. 



The President thought this a good idea, and hoped that at the next meet- 

 ing those members who had any specimens of the instruments would bring 

 them for inspection. 



Votes of thanks to Mr. Fullagar and Mr. Ingpen for their communications 

 were then unanimously passed. 



Announcements of the Annual Dinner, and other engagements for the 

 ensuing month w r ere then made, and the meeting terminated with a conver- 

 sazione, at which the following objects were exhibited : — 



Silky Earthmite by Mr. F. W. Andrew. 



Leaf of Urtica dioica ... ... ... ... „ Mr. T. H. Buffham. 



Plates of Star Fish „ Mr. A. L. Corbett. 



