241 



The thanks of the meeting were voted to Mr. Roiisselet for his 

 communication, 



Mr. C. D. Soar read a paper on a new species of Atax^ for 

 which he proposed the name A. Taverneri. 



The thanks of the meeting w^ere voted to Mr. Soar for his very 

 interesting paper. 



Mr. Lewis Wright then gave a very interesting de monstration 

 of the use of the latest improved form of lantern microscope as 

 showing the advances made in this method of class illustration 

 during the interval of fourteen years since he exhibited a lantern 

 microscope to the Club. These improvements had been largely 

 due to a better understanding of the relation between the aperture 

 of the condenser and that of the objective as explained by Mr. 

 E. M. Nelson. The condenser was now made of four lenses 

 instead of three, by which arrangement most of the spherical 

 aberration had been got rid of. The frame had been consider- 

 ably strengthened in order to obtain greater steadiness for the 

 fine adjustment, and the screen was made more highly reflective 

 by being coated with a film of silver. This he had at first made 

 with a plane surface, but found that the pictures in that case 

 could only be seen by persons sitting in front of the screen. 

 Subsequently he had finely ribbed or striated the surface in a 

 vertical direction, with excellent results, the screen being rendered 

 capable of showing the pictures equally well at a considerable 

 angle on either side. In addition to these improvements, much 

 better and more suitable object-glasses could now be obtained, 

 and the substitution of electric for limelight illumination had 

 enabled much higher powers to be efiectively employed than was 

 formerly possible. He regretted that the current available in 

 the room would not suffice to supply his electric lamp, so that he 

 should have to fall back upon the lime light ; and although he should 

 not with this be able to show the best effects attainable, possibly 

 the comparison between what he could now do and what he was 

 able to do fourteen years ago with the same means of illumination 

 would be satisfactory. Mr. Wright then showed a large number 

 of slides upon the screen under various powers, concluding the 

 exhibition with some very excellent views of opaque objects shown 

 with remarkable brilHancy and sharpness. 



The President said that the Club was greatly indebted to Mr. 

 Wright for giving them this very fine exhibition, and for the 



