464- Scientific Intelligence. 



that the relative change in the velocities u and v of the ions fol- 

 lows in the same sense and amount the changes in the pressure. 

 From the change in conductibility and the number denoting the 

 amount of migration, one can calculate the change in the velocity 

 of the ions. — Ann. der Physik., No. 10, 1901, pp. 315-330. 



J. T. 



12. Photometry of the Ultra- Violet rays. — The great intensity 

 of the light electric effects produced by an electric spark, leads 

 H. Kreusler to experiment with a view to determining whether 

 the phenomenon might not lead to a method in photometry. The 

 electrodes for the spark consisted of aluminum, zinc, and an 

 alloy of equal parts of zinc and cadmium, with addition of 5 per 

 cent of antimony. No constant light was obtained except in the 

 case of aluminum if both electrodes were of the same metal. 

 This constancy was obtained, however, if the negative pole was 

 made of aluminum. The photo-electric cell was that of Warbury, 

 consisting of suitable electrodes in an atmosphere of rarified 

 hydrogen. The measurements were carried out with the object 

 of determining the absorption coefficients of various gases and of 

 water. Although there were evidences of constant errors the 

 method seems a promising one.— -Ann. der Physik., No. 10, 1901, 

 pp. 412-423. j, t. 



II. Geology and Mineralogy. 



1. Glaciation in Tierra del Fuego and in the Antarctic. — In 

 a very interesting account of the Antarctic voyage of the 

 "Belgica" during the years 1897 to 1899, read before the Royal 

 Geographical Society by Henry ARgTowsKi, of the scientific 

 staff of the expedition, some observations are given in regard to 

 the ancient glaciers of Tierra del Fuego, and also of parts of 

 Graham Land and neighboring islands in the Antarctic directly 

 south of Cape Horn. In respect to Tierra del Fuego, the author 

 remarks that well-preserved traces of the former extension of the 

 glaciers were observed at numerous points. The bay of the great 

 glacier is a fine fiord opening into Darwin channel ; this fiord is 

 divided into basins by three large transversal moraines. He 

 adds : " The transversal moraines are not the only indications of 

 the ancient extension of the great glacier. They rather mark 

 with great clearness the stages of a rapid retreat of this immense 

 river of ice at the close of the glacial epoch. The sides of the 

 mountains which border the fiord bear roches moutonnees at con- 

 siderable altitudes, and one of the mountains has the character- 

 istic outline of a huge sheep's back surmounted by a small hillock. 

 This latter has sharp ridges, whilst all the rest of the mountain is 

 polished and planed by the erosive action of the ice. I have no 

 doubt that during the glacial epoch it was a nunatak rising above 

 the surface of the inland ice which covered the Darwin moun- 

 tains, and which certainly reached to this point. It was not 

 merely, therefore, the head of the fiord which was blocked with 



