252 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



in the stage-floor on to the mirror S 2 , whence they pass on to the 

 mirror S 3 , and thence from the lens L on to the object D. The light, 

 after transmission through the transparent object D, has the same 

 course as for the projection of the opaque object. For physical de- 



°^ 



^m. l-i.j r 







Sz 



Fig. 58. 



monstrations both the mirrors, S x S 4 , are put out of action, the front 

 wall of the apparatus is folded down, and direct projection is made 

 on to the screen. 



Evatt, Ev. J.— The Cameragraph : a Drawing Apparatus. 



Journ. Anat. Physiol., ser. 3, iii. No. 42 (1908) ipp. 335-6 (1 fig.). 



F.bastce, R. H. — Das Zeichnen mikroskopischen Objekte. 



Mikrokosmos, ii. (1908-9) hefte 1-2. 

 Heinstadt, O. — Spiegelkondensor u. paraboloid. 



Zeitschr. wiss. Mikrosk., xxv. (1909) pp. 188-94. 



Siedentopp, H. — Spiegelkondensoren. 



[Polemical writings as to priority of invention of mirror condensers and 

 paraboloids.] Tom. cit., pp. 195-8. 



Siede, W. — Hilfsapparate des mikroskopischen Zeichnens. 



Mikrokosmos, ii. (1908-9) hefte 1-2. 



(4) Photomicrography. 



Contribution to the Theory of the Photographic Web.* — H. 

 Calmers and L. P. Clerc, in discussing the* above theory, deal with a 



* Comptes Rendus, cxlvi. (1908) pp. 905-7 (2 figs.). 



