650 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



an alternating or a continuous current. The author gives several exam- 

 ples of stereoscopic views taken by his apparatus. 



NACHET PARIS') 



Fig. 88. 



Bom an, H. L.— Objekttisch-Goniometer fur das Dick-Mikroskop. 



Centralbl. f. Mineral., Geolog., u. Palaontog., 1910, p. 187. 



Leiss, C. — Verbessertes Kristallisations-Mikroskop mit Erhitzungs und Kiihl- 



verrichtung fiir projection. Zcitschr.f. Kristallograph., xlvi. (1909) 280 pp. 



Souza-Beandao, V. de — novo Microscopio da commissao do Servico Geo- 



logico. Communicates do Servico Geologico de Portugal. 



Lisboa : (1903) v. pp. 118-250. 



