SCIENCE 



Editoeial Committee : S. Newcomb, Mathematics ; R. S. Woodwakd, Mechanics ; E. C. Pickeeing, 



Astronomy; T. C. Mendenhall, Physics; E. H. Thueston, Engineering; Iea Eemsen, Chemistry; 



J. Le Conte, Geology; "W. M. Davis, Physiography; O. C. Maesh, Paleontology; W. K. Beooks, 



C. Haet Meeeiam, Zoology; S. H. Scuddee, Entomology; C. E. Bessey, N. L. Beitton, 



Botany; Heney F. Osboen, General Biology; C. S. Minot, Embryology, Histology; 



H. P. BowDiTCH, Physiology; J. S. Billings, Hygiene ; J. McKeen Cattbll, 



Psychology; DANIEL G. Beinion, J. W. Powell, Anthropology. 



Friday, June 3, 1898. 



CONTENTS: 



On a Flicker Pliotomeifr : Peofessoe Ogden N. 

 EOOD 757 



The New York Zoological Park: PEOFESSOE 

 Heney F. Osboen 759 



Engineering Notes : Peofessoe E. H. Thurston..764 



Current Notes on Physiography : — 

 Physical Geography of Neio Jersey ; Physiographic 

 Types: Peofessoe W. M. Davis 765 



Current Notes on Meteorology : — 



Cyclones of the Philippine Islands; Physiological 

 Effects of High Altitudes ; Fog on the North At- 

 lantic Ocean; Cloud Study and Photography: 

 E. Dec. Ward 766 



Owrrent Notes on Anthropology : — 



Ethnography of Western Asia; Bibliography of 

 Peru ; The Lamp of the Eskimos : Peofessoe 

 D. G. Beinton 767 



Scientific Notes and News : — 



Summer School of the Illinois Biological Station ; 

 The International Congress of Applied Chemistry; 

 General 768 



University and Educational News 773 



Discussion and Correspondence :— 



Color Vision : C. Ladd Feanklin. A Precise 

 Criterion of Species : Peofessoe C. B. Daven- 

 POET. Electrical Anaesthesia : De. E. W. Scrip- 

 tuee 773 



Scientific Literature : — 



Lockyer on the Sitn's Place in Nature : Peofes- 

 soe Edwin B. Feost. Astronomy: PEOFESSOE 

 M. B. Snydee. Rollmaym's Entwickhings- 

 geschichte des Menschen : De. AlfeedSchapee. 

 Titchener's Primer of Psychology : Peofessoe H. 

 C. Waeeen 777 



Scientific Journals 782 



Societies and Academies : — 



The Chemical Society of Washington : William 

 H. Krug. The Academy of Natural Sciences of 

 Philadelphia: Dr. Edward J. Nolan 782 



MSS. intended for publication and books, etc., intended 

 for review should be sent to the responsible editor, Prof. J. 

 McKeen Cattell, Garrison-on-Hudson, N, Y, 



ON A FLICKER PHOTOMETER. 



In the September number of the American 

 Journal of Science for 1893 I described a 

 photometric method founded on flickers 

 which I had proved to be independent of 

 color, and stated that there did not seem to 

 be any reason why it should not be applied 

 to ordinary photometric work. In January, 

 1896, Professor F. P. Whitman published, 

 in the Physical Review, an account of a 

 photometer with a revolving disc of card- 

 board, in which this flicker method was 

 utilized with more or less success. After- 

 wards I constructed and experimented with 

 five different forms of flicker photometers, 

 and in November, 1896, read a paper on the 

 subject before the National Academy of 

 Sciences. 



I propose here to give a short account of 

 one of these forms, and to mention a few 

 experiments that were made with it by 

 myself and others. 



The two sides of the white, upright, 90° 

 prism, P, are illuminated with the lights to 

 be compared, coming from the incandescent 

 lamps L and L', and the flicker is brought 

 about by the rapid motion of the cylindrical 

 lens, or biprism of small angle, C. This is 

 caused to oscillate horizontally bj' a train 

 of toothed wheels, W, which can either be 

 turned by hand, or better by a small elec- 

 tromotor, E, the speed of which is regu- 

 lated by a friction break. When the ap- 

 paratus is in action the two illuminated sides 



