636 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



pillar moved by rack-and-pinion for focusing. In Ellis's Aquatic 

 Microscope the stem for carrying the lens-holder passes through a socket 

 at the back of the pillar, but in the instrument it passes down a hole in 

 the centre of the inner pillar. These alterations in the original design were 

 referred to by Adams in his Essays on the Microscope (1787). Another 

 alteration was the making of the stage removable to economise space in 

 the case. There are six lenses, two being provided with lieberkuhns. 



The case is covered with red leather instead of the fish-skin so 

 commonly used at that period. The instrument was said by the dealer 

 who sold it many years ago to have been the celebrated Dr. Jenner's 

 Pocket Microscope. 



A very similar Microscope made by Bate was presented to the Society 

 by Mr. E. B. Stringer, and is figured and described in the Journal for 

 1904, p. 354. 



Pocket Botanical and Universal Microscope. — This instrument 

 (fig. 139) was presented to the Society by Mr. C. Lees Curties. It was 



Fig. 139. 



made by W. and S. Jones, and is figured and described in Adams' Essays 

 on the Microscope, 2nd Edition, 1798, as a Pocket Botanical and Uni- 

 versal Microscope. It is evidently an improved form of the " Common 

 Botanical Microscope," described in the first edition of Adams' work, 

 1787, which had only two lenses and no adjustment screw to move the 

 stage. This example is well and neatly made, has three lenses which 

 can be superposed one over the other, and also a focusing screw which 

 is clamped to the stem and moves the stage. The stem slides in a 

 square brass socket screwed on to an oval ebony base. 



Wilson Screw-Barrel Simple Microscope. — This instrument (fig. 

 140) was presented by Mr. C. Lees Curties and was exhibited with the 



