ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 



97 



SiEDENTOPF, H. — TJeber ein neues physikalisch-chemisches Mikroskop (Mikros- 

 kopie bei hohen Tamperaturen). 13. Hauptversamml. d. Bunsen-Ges. f. angew. 

 physik. Chemie. Zeitschr. f. Elektrochemie, xii. (1906) p. 593. 



ZwiNTz, J., & O. Thien- 

 Mikroskope. 



-TJeber einen neuen elektrisch-heizbaren Objekttisch fiir 



Centralbl. Bakt., xlii. (1906) p. 179. See also 

 Zeitschr. tviss. Mikrosk., xxiii. (1906) p. 332. 



(31 Illuminating: and other Apparatus. 



Siemens - Schuckert Projection Apparatus.* — The designs of the 

 Siemens-Schuckert apparatus are intended to meet the projection require- 

 ments of all kinds of instruction and for audiences large or small. They 



FiG.'lO. 



Fig. 11. 



are suitable not only for Microscopic and physical demonstrations, but 

 also for the exhibition of spectral and other optical phenomena. The 

 most suitable light-source is the electric arc, both on account of its 



Fig. 12. 



Fig. 13. 



simplicity as well as for its certainty. The lamp may be either the 

 Siemens-Schuckert constant-current or variable-current lamp, fitted in a 

 well-ventilated case which carries the optical equipment on its front wall 

 The lamps may be hand-regulated or automatic. The 



hand-regulated 



* Siemens-Schuckert (Berlin), Special pamphlet, No. 23 (8906). 

 Feb. 20th, 190? H 



