January 13, 1905.] 



SCIENCE. 



67 



The first paper of the evening was by Pro- 

 fessor J. J. Stevenson, upon ' The Island of 

 Spitzbergen and its Coal,' and was illustrated 

 by lantern slides. In introducing his subject, 

 the speaker described briefly the coast of 

 northern Norway and its geology, and referred 

 in some detail to Bergen, Hammerfest and 

 other cities. Spitzbergen was then taken up, 

 and its coals and their geological relations 

 were passed in review. The coal beds are of 

 Jurassic age, and the coal is- peculiar in that 

 it partakes of the characters of the lignites as 

 well as of the true coals. 



The second paper on the program was by 

 Professor James F. Kemp, on ' The Titanif- 

 erous Magnetite in Wyoming.' On account 

 of the lateness of the hour, the speaker pre- 

 sented his topic only in abstract. The mag- 

 netite occurs in two places, fifteen and twenty 

 miles north of Laramie, Wyoming, the former 

 and smaller occurrence being near the Shan- 

 ton ranch, the latter and larger being on Chug- 

 water Creek. Both are in wall-rock of an- 

 orthosite which is practically indistinguishable 

 from anorthosite occurring in the Adiron- 

 dacks. The ores range from 20 per cent, to 

 40 per cent. TiO,. Thin sections show that 

 they contain green spinels, and one slide pre- 

 sents much olivine. They can be most reason- 

 ably explained as intrusive dikes. In this 

 view the speaker agreed with Waldemar Lind- 

 gren, who has published a brief note regarding 

 them. James F. Kemp, 



Secretary pro tern. 



The section held a special meeting Decem- 

 ber 2, 1904, with Vice-president Kemp in the 

 chair and two hundred members and visitors 

 in attendance. The meeting was called to 

 order at 8:25 p.m. and the program of the 

 evening was at once taken up. This consisted 

 of a lecture by Professor Albrecht Penck, of 

 the Imperial University at Vienna, who is an 

 honorary member of the academy. 



The speaker discussed ' The Glacial Surface 

 Features of the Alps,' and gave a brief sum- 

 mary of some of the results of the twenty 

 years of masterly work which has been done 

 by him and under his direction in the Tyrol. 

 Professor Penck described in popular language 



the nature of the valleys of the Alps and 

 showed by means of lantern slides and a dia- 

 gram how the glaciers have widened and 

 deepened portions of their rocky basins and 

 produced lakes. 



After a vote of thanks to the distinguished 

 guest of the evening, the section adjourned. 



Edmund Otis Hovey, 



Secretary. 



THE PHILOSOPHICAL SOCIETY OF WASHINGTON. 



The 592d meeting was held December 10, 

 1904. 



The first paper was read by invitation by 

 Mr. H. H. Kimball, of the Weather Bureau, 

 on ' Variations in Insolation and in the Polar- 

 ization of Blue Sky-light, during 1903 and 

 1904.' Observations with an Angstrom pyr- 

 heliometer have been maintained by the 

 Weather Bureau at Washington since April, 

 1903. Comparison with previous observations 

 at Providence, R. I., and Asheville and Black 

 Mountain, N. C, indicate that the quantity 

 of solar radiation reaching the surface of the 

 earth on clear days during 1903 was consid- 

 erably less than during 1902 and 1904, the 

 deficiency from April to September being 16 

 per cent, as compared with 1902, and 9 per 

 cent as compared with 1904. 



Observations with a Pickering polarimeter 

 indicate that there have been corresponding 

 fluctuations in the polarization of blue sky- 

 light, the percentage of polarization at a 

 point on a vertical great circle passing through 

 the sun and 90° from it, having averaged 

 49.6 per cent, from May to October of 1904, 

 as compared with 40.6 per cent, during the 

 same months of 1903. 



The work of the astrophysical observatory 

 of the Smithsonian Institution and numerous 

 European observations were quoted, showing 

 similar deficiencies in insolation, in the trans- 

 missibility of the atmosphere, and in the 

 polarization of blue sky-light, during 1903. 



The subject was considered to be one well 

 worthy of investigation by meteorologists. 



Mr. J. F. Hayford, of the Coast and Ge- 

 odetic Survey, presented some recent results 

 on ' The Computation of Deflections of the 

 Vertical from the Surrounding Topography.' 



