80S SUMMARY OF CURRENT RESEARCHES RELATING TO 



a meeting at which " the whole of the opticians in London bo invited to 

 show the special forms of instruments they consider most useful to 

 students" — by " Prismatique " — A. Caplatzi, that the foreigner can 

 underbid us because he is belter trained, more industrious, soberer, and 

 more provident, &c., &c. — by ''Prismatique" (2) that most of the 

 foreign work is " make-believe," while our own is genuine — E. Holmes 

 -A. K. C.-W. S. Franks—" Orderic Vital."] 



Engl. Mech., XLIII. (1886) p. 580 ; XLIV. (18SG) pp. 16, 39, 6G, 88, 111. 

 Fasoldt, C. — Resolution of 200,000 lines to the inch. 



["We have lately, with the use or aid of the second fine adjustment and 

 internal illumination, resolved 200,000 lines per inch with homogeneous- 

 immersion 1/16 in., and also with 1/12 in. homogeneous. Should you 

 find or hear of an 'incredulous Thomas,' send him here. Only provided 

 he has got first-class eyes, we will show him the 200,000. Furthermore, 

 there is no reason for ridiculing, as not only one but a number have seen 

 them, and would make affidavits accordingly if desired."] 



Micr. Bulletin (Queen's), III. (1886) p. 32. 

 Giles, G. W. M. — On Marine Collecting with the Surface-net. 



[Describes and figures a Botterill life-cell and aerating apparatus. — Also 

 remarks on the handiest form of simple Microscope, and on examining 

 and preparing the objects collected.] 



Sci.-Gossip, 1886, pp. 79-80 (2 figs.). 

 G o w e r, H. D. — How to make a Tint-reflector. 



[Wooden pill-box and thin glass cover; or thin silvered glass, if the image 

 is to be thrown down on a sheet of paper.] 



Sci.-Gossip, 1886, p. 172 (4 figs.). 



Grot ii, P. — Physikalische Krystallographie und Einleitung in die Krystallo- 



graphische Kenntniss der wichtigeren Substanzen. (Physical Crystallography 



and introduction to the crystallographic knowledge of the more important 



substances.) 



[Part I. The physical properties of crvstals. Part II. The geometrical 

 pi operties of crystals. Part III. (pp. 5*43-674, figs. 565-621). The appa- 

 ratus and methods for crystallographic-phys'.cal researches. A. Gonio- 

 meter and refractometer. B. Polarization apparatus. C. Microscopes 

 and microscopical measuring apparatus. (Includes Koch's Microscope for 

 determining the elasticity coefficients, post.) D. Cutting and grinding 

 apparatus.] 



2nd ed., xv. and 710 pp., 631 figs, and 1 pi. (8vo, Leipzig, 1885). 

 Heurck's (H. van) Photographs of Amphipleura and Nobert's Bands. 



[Includes note by Dr. Roystou-Pigott that " they have in my opinion no 

 equals."] 



Amer. Mon. Micr. Journ., VII. (1886) p. 138. 

 „ „ Method of taking Photo-micrographs. [See infra, p. 900.] 



Engl. Mech., XLIII. (1886) pp. 548-9, from Brit. Journ. of Phot. 

 Hitchcock, R. — Photo-micrography. VII. 

 [4. Developing contd.~] 



Amer. Mon. Micr. Journ., VII. (1886) pp. 131-3, 141-2. 



Jennings, J. H. — How to photograph Microscopic Objects. A Manual for the 



practical Microscopist. (8vo, New York, 1886.) 



Kerber, A. — TJeber die Chromatische Korrektur von Doppelobjektiven. (On the 



chromatic correction of double objectives.) 



Central-Ztg.f. Opt. u. Mech., VII. (1886) pp. 157-8 (2 figs.). 

 "Lens." — Black Illumination without Parabola. 



[The writer racked back and finally removed the parabola without losing 

 the black ground ! — the explanation being that, instead of placing the 

 mirror in the axis, he had placed it excentrically.] 



Engl. Mech., XLIII. (1886) pp. 509-10. 

 Levi, J. N.— Photo-micrographic Work and Apparatus. 



Bull. Rochester Acad. Sci., 1886, pp. 10-21. 



