Geology and Mineralogy. 363 



him to finish his task. The completion of the work, therefore, 

 has been placed in the hands of his associate, Dr. Exner, who 

 with much thoroughness and industry has prepared a well- 

 arranged digest of the special subjects to be covered. As this 

 field, however, is one to which he had not devoted particular 

 attention, he disclaims any attempt at originality of presentation, 

 except in regard to Lord Rayleigh's theory of the blue color of 

 the sky. Some of the topics treated are as follows: The apparent 

 form of the firmament ; atmospheric refraction and the connected 

 phenomena, as the Fata Morgana, scintillation, etc. ; halos and 

 rainbows and their explanation ; the color and polarization of the 

 sky, the weakening of light in the atmosphere and twilight phe- 

 nomena. 



II. Geology and Mineralogy. 



1. Publications of the IT. S. Geological Survey, Geo. Otis 

 Smith, Director. — Recent publications of the TJ. S. Geological 

 Survey are noted in the following list (continued from vol. xxviii, 

 p. 557). 



Folios. — Geological Atlas of the United States. — No. 167. 

 Field edition, in octavo form. Trenton, New Jersey-Pennsyl- 

 vania Folio. Description of the Trenton Quadrangle : F. Bas- 

 com, N. H. Darton, H. B. Kummel, W. B. Clark, B. L. Miller, 

 and R. D. Salisbury. Pp. 185 ; 2 maps. Structure section 

 sheet, columnar sections, 3 figures. 



No. 169. Watkins Glen-Catatonk Folio, New York ; by 

 Hrnry S. Williams, Ralph S. Tarr, and Edward M. Kindle. 

 Pp. 33, 3 colored maps, 37 figures. 



Professional Papers. — No. 65. Geology and Water Re- 

 sources of the Northern Portion of the Black Hills and Adjoin- 

 ing Regions in South Dakota and Wyoming ; by N. H. Darton. 

 Pp. 105, 24 plates, 15 figures. See p. 267. 



Mineral Resources of the United States. Calendar year 

 1908. Parti — Metallic Products. Pp. 816, 2 plates, 3 figures. 

 Part II — Non-Metallic Products. Pp. 899, 1 plate, 6 figures. 

 These important volumes, each with its own index, bring together 

 the numerous separate chapters, prepared by many different 

 authors, which have already been issued in advance. The gen- 

 eral summary of mineral production in 1908, with which Part I 

 opens, has been prefaced by W. T. Thom. 



Bulletins. — No. 378. Results of purchasing Coal under Gov- 

 ernment Specifications; by John Shober Burrows. With a 

 paper on Burning the Small Sizes of Anthracite for Heat and 

 Power Purposes ; by Dwight T. Randall. Pp. 44. 



No. 386. Pleistocene Geology of the Leadville Quadrangle, 

 Colorado ; by Stephen R. Capps, Jr. Pp. 99, 7 plates, 18 

 figures. 



