ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



297 



Fig, 45. 



inyMTIIllllfllillffEM^ 



(3) Illuminating Apparatus. 



Jones's Radial Swinging Tail-piece.* — The principle of causing the 

 illumination to move radially upon the object from the axis to near the 

 horizon and above, as illustrated in Grubb's Sector Microscope,! and 

 subsequently by Nachet (Thury), Zentmayer, Tolles, Bulloch, and others, 

 appears to have been anticipated in the last century in a Lucernal Micro- 

 scope, designed by " the Eev. 

 John Prince, LL.D., now of 

 Salem, Massachuset's States, 

 North America," and con- 

 structed by W. and S. Jones, 

 the application of the lamp 

 being suggested by " Mr. John 

 Hill, Wells, in Norfolk." J 



Fig. 45 shows the tail- 

 piece as figured by Adams in 

 plate ix. fig. 5 of the second 

 edition of his ' Essays on the 

 Microscope.' The stage F is 

 supported by a rod passing 

 through a socket M, and 

 attached to a bar, forming a 

 continuation of the limb 

 carrying the projection-box 

 or camera of the Microscope ; 

 G I K is the tail-piece con- 

 nected with the socket M, 

 and strengthened by the 



bracket H, carrying condensers 1 and 2, and the lamp L. The tail-piece 

 swings laterally round the axis of F, and thus gives radial illumination 

 upon the object on the surface & a of the stage. 



In what appears to have been an original form of the apparatus which 

 we have seen, a mirror was fitted to slide upon the tail-piece, but no lamp 

 was applied. To the apparatus furnished with a lamp a tablet is attached, 

 notifying that Mr, John Hill had devised the arrangement. 



Bausch & Lomb Condenser and Substage, [Post.l 



The Microscope, VII. (1887) p. 16 (1 fig.)- 

 N., W. J.— The Two Mirrors. IV. [Posf] 



Sci.-Gossip, 1887, pp. 25-7, 52-4 (3 figs.) (^contd.). 

 Strieker's Electric Lamp. 



[" In lecturing before the Society of Natural History at Berlin, Prof. Strieker haa 

 employed with much success an electric lamp of 4000 candle power for the pro- 

 jection of microscopic sections upon a screen, employing a magnifying poVrer of 

 6000 to 8000 diameters. It is stated that the definition obtained is very satis- 

 factory." Cf. Journal, 1886, p. 502.] 



Science, IX. (1887) p. 55, and see Pe, supra (1). 



(4) Other Accessories. 



Haswell's Rotating Stage and Circular Slides for large Series of 

 Sections. — This apparatus was more especially designed by Mr. W. A. 

 Haswell for the purpose of enabling students conveniently to examine 

 series of sections of objects which they have not the opportunity of section- 

 ing for themselves. It is thus more particularly intended for special 



* Society of Arts Cantor Lectures on the Microscope, by J. Mayall, junr. (reprint in 

 collected form), 1886, p. 58 (1 fig.). t See this Journal, 1880, p. 105G. 



X See Adams's ' Essays on the Microscope,' 2nd ed., 1798, p. 84. 

 1887. X 



