Septejibee 20, 1895.] 



SCIENCE. 



35c 



13. Color Definitions for the Standard Dic- 

 tionary (10 m.), by W. Hallock and E. 

 Gordon. Disks painted with English ver- 

 milion, minei'al orange, light chrome yellow, 

 emerald green and artificial ultra-marine 

 blue, in a thick solution of gum arable, have 

 had their wave-length determined. These 

 combined with white, and a disk covered 

 with lamp black and shellac, enable one to 

 place such combinations upon a rotation 

 machine as to match any color in nature or 

 art. This process was applied to the study 

 of 6j000 samples of colored objects resulting 

 in formulae for some 500 named colors. 



14. On Standard Colors (20 m.), by J. H. 

 PiLLSBUEY. The author urges correct and 

 scientific teaching of color especially in 

 early youth, approving the use of Maxwell 

 disks, printed red, orange, yellew, blue and 

 violet, by lithography, with black and white. 



15. Significance of Color Terms (15 m.), by 

 J. H. PiLLSBURY. The uncertainty attached 

 to color nomenclature was pointed out and 

 the desire expressed that it should be re- 

 moved by the introduction of a method of 

 definition similar to that explained in the 

 previous paper (ISTo. 14). Numerous illu- 

 strations were given showing varieties of 

 colors, including some well-known flowers. 



16. On the Comparison in Brightness of Dif- 

 ferently Colored Lights and the ^Flicker Photom- 

 eter^ (20 m.), by Frank P. Whitman. A 

 very interesting and successful comparison 

 test of the Rood flicker photometer, an 

 ingenious device of rotating semi-disc, al- 

 lowed the easy and accurate comparison of 

 lights, etc., upon an ordinarj^ photometer 

 bench. The tests upon the colors of the 

 spectrum brought out the accepted maxi- 

 mum of luminosity in the yellow, and also 

 showed a slight increase in luminosity at 

 the extreme violet. It must, however, be 

 said that these measurements were made 

 upon colored papers and not upon the spec- 

 trum itself. 



17. Observation on the Relations of Certain 



Properties of Line Spectra to the Physical Con- 

 ditions under ivhich they are Produced (20 m.), 

 by J. F. MoHLER and W. J. Humphries. 

 Experimenting upon the spectra of metals 

 under pressures of air up to 15 or 20 at- 

 mospheres, certain widenings and displace- 

 ments of the lines were noted, and an in- 

 creasing similarity in appearance to the 

 solar spectrum. 



18. An Experimental Investigation of ike 

 Rotary Field (20 m.), by H. S. Carhart. 

 An iron ring wound with a continuous coil 

 tapped at four, six, or more points combined 

 with an ingenious commutator furnished a 

 rotary field that could be stopped and 

 studied at any instant. The photographs 

 of iron filings in the field, show a ' measur- 

 ing worm motion ' of the poles, with no 

 essential difierence between the two and 

 three phase connection. 



19. Electrolytic Reproduction of Resonators 

 (5 m.), by W. Hallock. A wax ball is 

 turned the size and shape of the spherical 

 resonator, and then copper plated. After 

 melting out the wax, the resonator is tuned 

 by cutting off the lip of the mouth. 



20. A Photographic Method of Comparing 

 the Pitch of Tuning Forks (5 m.), by "W. 

 Hallock. Each fork is clamped before a 

 manometric capsule, bowed, and the flames 

 photographed, and the relative number of 

 vibrations counted. 



21. Illustration of Gems, Seals, etc. (5 m.), 

 by W. Hallock. An impression of the 

 gem is taken in the transparent wax, used 

 first by 0. N. Rood, and this is photographed 

 by transmitted light in an enlarging camera. 



22. An Examination of the Statement of 

 Maxwell that all Heat is of the Same Kind 

 (15 m.), by Wm. A. Rogers. The author 

 argues, from his observations with his inter- 

 ferential comparator, that heat of radiation 

 is different from heat of air contact and 

 should be measured in a diflferent unit. 



23. Phenomena of Electric Waves Analogous 

 to those of Light with a Diffraction Grating 



