316 



SUMMARY OF CURRENT RESEARCHES RELATINQ TO 



An improved Sciopticon is announced * by O. Wigand, the 

 principal features of which (for microscopical purposes) are(l) that 

 there is a more perfect combustion of the gases of the petroleum lamp, 

 and therefore a more intense white light, and (2) that none of the 

 reflector is covered up by the frame of the lantern. 



L. Edinger,t as noted anfe, p. 147, uses the sciopticon for readily 

 making drawings of large sections under low powers. The rays are 

 received by a mirror inclined at an angle of 45°, and the image thrown 

 direct on the drawing-paper. 



C. J. Taylor J finds a valuable screen is made of a sheet of French 

 tracing-paper, of a kind which possesses a remarkably dull, non- 

 reflecting surface. With this screen and only an oil-lamp lantern, it 

 is quite easy to show pictures well to a couple of hundred people in 

 a room fairly well lighted — sufficiently lighted indeed to enable note- 

 taking or reference to books to be accomplished with perfect ease — 

 provided that extraneous lights are not placed behind the screen. 



"Westien's Universal Lens-holder.§ — A. v. Brunn describes H. 

 Westien's lens-holder (fig. 65). 



To the standard A is attached the arm B by the " patent junction 



Fig. 65. 



clamp Kl." The arm can be moved (1) up and down the standard, 

 (2) round it, (3) backwards and forwards through the clamp in the 

 direction of the arrows a a, or (4) round the axis of the clamp, as also 

 shown by the arrows h h. These various movements are all controlled 



* Central-Ztg. f Optik u. Mech., iv. (1883) (1 fig.). 



t Zeitschr. f. Wiss. Mikr., i. (1884) pp, 250-1. 



X Nature, xxxi. (1885) pp. 388-9. 



§ Arch. f. Mikr. Anat., xxiv. (1884) pp. 470-1 (1 fig.). 



