August 14, 1896.] 



SCIENCE. 



193 



month in the light, and these spots were par- 

 ticularly abundant in those parts (antennae and 

 claws) which had been accidentally lost and 

 were in course of restoration. C. L. F. 



COLOR PHOTOGRAPHY. 



M. Georges Adolphe Richard states in the 

 Comptes Eendus that he has solved the problem 

 (which has hitherto seemed insoluble) of repro- 

 ducing and making permanent three separate 

 jjroofs of the picture in the Becquerel process 

 of color photography, and of superimposing 

 them upon a single plate. His process consists 

 in substituting for the reduced silver, which is 

 deposited in the collodion at varying depth, 

 corresponding to the crests of the standing 

 waves produced by light of three fundamental 

 colors, a coloring matter of the corresponding 

 tone. There are two ways of accomplishing 

 this : (1) the reduced silver is transformed into 

 a salt which is capable of fixing or of precipita- 

 ting the coloring matter in question, or (2) it is 

 transformed into a salt which reacts upon the 

 carbon derivatives and forms an artificial color- 

 ing matter in the place and of the thickness re- 

 quired. Three plates are formed for the three 

 fimdamental colors, the middle one on a gelatine 

 film and the other two on glass. The superposi- 

 tion of these three layers in the exact place re- 

 quired oflfers no difficulty, and the colors are of 

 absolute stability. The combined plate can, of 

 course, be looked at at any angle, unlike the 

 plate produced by the Becquerel process in its 

 original form. At the same time comes the in- 

 formation that a Chicago photographer has per- 

 fected the Joly process ; it would seem that the 

 moment is not far distant when photographs 

 which reproduce the natural colors of objects 

 will be easily witliin reach. C. L. F. 



THE EYESIGHT OF ENGLISH SCHOOL CHILDREN. 



A REPORT has been presented to the British 

 Education Department by Mr. Brudnell Carter 

 on the vision of 8,125 children attending twenty- 

 five elementary schools in London. The re- 

 fraction of the eyes had in many instances 

 to be determined from a simple ophthalmo- 

 scopic inspection owing to the objections raised 

 by parents to the use of mydriatics, and iuter- 



ance and other causes. 3,181 children, or 39.15 

 per cent., were found to have normal vision in 

 both eyes; 1,016, or 12.5 per cent., had normal 

 vision in the right eye and subnormal in the 

 left; 700, or 8.6 per cent., had normal vision in 

 the left eye and subnormal in the right; and 

 3,228, or 39.7 per cent., had subnormal vision 

 in both eyes. Comparing the sexes, the total 

 was made up of 3,928 boys and 4,197 girls ; of 

 these 43.7 per cent, of the boys had normal 

 vision in both eyes, and 33.4 per cent, of the 

 girls. 



Mr. Carter is of the opinion that the eyes of 

 London school children generally are not in any 

 way injuriously affected by the conditions of 

 elementary school life. Myopia is not of fre- 

 quent occurrence, and Mr. Carter has failed to 

 find any evidence of its progressive increase 

 from younger children to the elder ones, or any 

 correspondence between the degree and the 

 prevalence of the defect and the quality of, the 

 lighting in the schools where it Avas found. He 

 holds that the prevalence of subnormal vision 

 is due to the fact that children so rarely look at 

 distant objects. 



THE OBSERVATORY OF YALE UNIVERSITY. 



The report of Dr. W. L. Elkin, who since it 

 was written has been made director of the Ob- 

 servatory, to the managers for the year 1895-6, 

 is as follows : 



' ' The series of measures for the purpose of 

 detecting possible large parallaxes of stars with 

 large proper motion has been carried on during 

 the past year by Dr. Chase and myself. A 

 few stars have been added to the list to fill 

 up the gaps which presented themselves in the 

 course of observing. As at present planned, 

 the work will be completed probably in the 

 course of 1807, as far as the observations are 

 concerned. 



"The series on the parallaxes of the first 

 magnitude stars is, as stated in my last report, 

 practically brought to a close, and only a few 

 points of discussion remain to be revised. 



"A considerable portion of my time has 

 been devoted to a final revision of the discus- 

 sion of the work on Iris as it passed through 

 the press. This has now been accomplished, 

 and the work will shortly appear as Part IV. of 



