304: Scientific Intelligence. 



scientific and the technical resources of the country to supply the 

 needs of the naval and military forces. This volume has been 

 prepared by the Ordnance Division of the War Department and 

 is designed to present a record of the investigations made 

 and the results obtained at that time. The introductory chap- 

 ter outlines the personnel of the work undertaken, the fac- 

 tories engaged and the production achieved. Chapter 2 is 

 devoted to the composition of optical glasses and their various 

 physical characteristics with extensive tables and diagrams show- 

 ing the chemical analysis and optical constants. The third 

 chapter describes the technical processes involved in mixing, 

 melting, and annealing the glass, and is illustrated with numer- 

 ous photographs of these operations taken in the factory. In 

 chapter 4 the methods used for the inspection and detection of 

 defects are explained. Chapter 5 describes the processes by 

 which the lenses and the prisms are shaped, ground and polished. 

 The sixth chapter explains the ways in which the completed opti- 

 cal train is tested for satisfactory performance. The last chapter 

 contains a review of the optical instrument situation during the 

 war and the success which was attained in the production of these 

 instruments. 



The book will be a highly informing one for any person who 

 is at all interested in optics and contains much data probably not 

 accessible elsewhere. f. e. b. 



II. Geology. 



1. Notes on Arctic Ordovician and Silurian Cephalopods; by 

 Aug. F. Foerste. Bull. Denison Univ., vol. 19, pp. 247-306, pis. 

 27-35, 1921. Revolution vs. Evolution: The Paleontologist Renders 

 his Verdict; by Kirtley F. Mather. Ibid., pp. 307-323.— The first 

 paper is a detailed study of twenty-eight nautilids, of which sev- 

 enteen occur in Arctic America, Bear Island or Spitzbergen. 

 There are ten new forms and two new genera, Ellesmeroceras and 

 Leurorthoceras. This work is a praiseworthy beginning toward 

 a revision of all American Ordovician and Silurian cephalopods, 

 which the author has in contemplation. The second paper is 

 philosophical in nature, dealing with the course animal life has 

 taken in its evolution throughout the geological ages. The 

 author's conclusions are in part: 



"The crisis recorded in the rocks of latest Paleozoic Age, was 

 forced upon the land animals by changes in climate and environ- 

 ment ; it was successfully passed by creatures who specialize in 

 the adaptation of their bodies to cold and drought, and who 

 escaped from the crowded confines of the sea to the almost unin- 

 habited silences of the land. The 'revolution' involved in the 

 dethronement of the reptiles and the exaltation of the mammals 



