June 17, 1892.] 



SCIENCE. 



339 



Eev. Moses Harvey of St. John's, Newfoundland, and a 

 new fellow of the society, contributed a most important 

 paper " On the Artificial Propagation of Marine Food-Fishes 

 and Edible Crustaceans." This paper deals extensively with 

 the rise and progress of pisciculture, the importance of 

 modern fish-culture, artificial increase of fresh-water and 

 anadromous fishes, also the results obtained by private and 

 national enterprises. Aqui-culture may yet approach agri- 

 culture in usefulness. Scientific study of fish-life and the 

 physics of the sea bore intimately on the value of fisheries. 

 The work carried on by the United States Fish Commission, 

 by the Canadian Department of Fisheries, and the success of 

 IS'orwegian pisciculture, along with the great results already 

 obtained by lobster hatching with the Nielson process, are all 

 •discussed by Dr. Harvey, and many important facts of great 

 economic value are noted. The paper ends by calling atten- 

 tion to the need of fishery schools and biological stations in 

 Canada, for the study of fish, and other animals of the sea, 

 of most importance to man. These are of national impor- 

 tance. 



Mr. James Fletcher, F.L.S., and Dominion entomologist, 

 contributed two papers in that branch of work. The first 

 was entitled, " Report on a Collection of Coleoptera made on 

 the Queen Charlotte Islands by Eev. J. H. Keen and J. 

 Fletcher;" the second, " The use of Arsenites as Insecticides." 

 Both proved highly interesting and useful. 



At the closing general meeting of the society the following 

 were elected to ofiice: president, Dr. J. G. Bourinot; vice- 

 president. Dr. George M. Dawson ; honorary secretary, Mr. 

 James Fletcher; honorary treasurer, Dr. A. E. C. Selwyn. 

 In Section III. and IV., which deal more particularly with 

 science and scientific work, the following were elected ofii- 

 •cers of sections: Section III., president. Professor E. J. 

 Chapman; Section IV., president, Mr. Whiteaves; vice-pres- 

 ident, Professor Macoun; secretary. Professor D. P. Penhal- 

 Jow. 



The discussions which took place on the papers read were 

 lively throughout, and interesting points were brought to 

 light. 



The Eoyal Society of Canada unanimously agreed to in- 

 vite the Geological Society of America to meet in Ottawa in 

 December. 



NOTES ON STAR PHOTOGRAPHY. 



BY ROMTN HITCHCOCK. 



The writer would beg the indulgence of those astronomers 

 who may be induced by the title to read these lines in the 

 expectation that they are the results of practical work in 

 photographing stars. These, unfortunately, he cannot give; 

 but inasmuch as the astronomers have so liberally availed 

 themselves of the simplified methods of modern photography, 

 which they can carry out more or less satisfactorily them- 

 selves, it is only fair that photographers should have a word 

 to say now and then in behalf of the branch of investigation 

 which they represent. By the term photographers I do not 

 mean mere operators in the dark-room, nor amateurs who 

 ■can make fine pictures, nor anything of the sort. I mean 

 what may be best designated as photographic chemists, who 

 are practically familiar with the subject from a chemical and 

 ■scientific standpoint, and capable of conducting researches 

 and designing and using apparatus for that purpose. It is 

 •certainly true that astronomers generally have neglected the 

 surest means of achieving the highest success and advance- 

 ment in their photographic work, in that tliey have under- 



taken to carry out themselves that part of it which ought to 

 engage the attention of the highest skill and knowledge of 

 the photographic chemist. So little is this fact recognized, 

 that we actually sent a party to photograph the last eclipse 

 of the sun in Japan, absolutely without either a photogra- 

 pher or a photographic outfit. So far from any effort to 

 utilize the latest knowledge and methods for eclipse work, 

 that expedition might easily have proved a total failure from 

 the absence of the essentials for common work. When the 

 expedition to the coast of Africa was fitted out, great atten- 

 tion was given to designing certain forms of apparatus; but, 

 if I recollect aright, no photographer was chosen until a few 

 days before its departure. Then a certain commercial brand 

 of color-sensitive plates was chosen, but on what grounds, 

 or whether the spectrum sensitiveness of those plates was 

 tested at all, I have never learned. There will be an excel- 

 lent opportunity for eclipse work next year; but if anything 

 new is to be learned from it, the work of preparation should 

 begin now in a photographic laboratory. We have apparatus 

 enough, or we know perfectly well what is required, but we 

 do not know the photographic process best adapted to the 

 work. 



It may be but an idle dream, but I hope to see a photo- 

 graphic laboratory established in connection with one of our 

 large observatories or universities, not for routine work but 

 for purely scientific research in photographic chemistry, such 

 as will enable us to apply the latest knowledge to astronomi- 

 cal and spectrographic work. 



An announcement has recently appeared, to the effect that 

 the French astronomers have begun to doubt the value of 

 negatives of stellar bodies taken on orthochromatic plates, 

 because the stellar discs are surrounded by a strong aureola 

 due to the aberration of the red rays of the objective. For 

 this reason the permanent committee on the chart of the 

 heavens has decided to exclude orthochromatic plates for such 

 work. 



I presume everyone finds some satisfaction in saying, "I 

 told you so." The announcement leads me to publish now 

 an article, on this subject, which was written in Japan be- 

 tween four and five years ago. It was perfectly clear to me 

 at that time, that color-sensitive plates were being used in 

 astronomical work when the very opposite kind of plates 

 would have been much better for the purpose. Instead of 

 extending the sensitiveness, it should have been restricted 

 as much as possible. My article was not published because 

 I deemed the facts too obvious to require discussion. But 

 since M. Leon Vidal, editor of Le Moniteur de la Photogra- 

 phie, has taken, as I believe, an erroneous view of the matter 

 in opposition to the practical results of the astronomers, I 

 have looked up my old MS., and publish it herewith without 

 change. 



I would add that the opinion then expressed as regards the 

 future of collodion plates, for all scientific work, has been 

 greatly strengthened by the results of later investigations. 



The article referred to is as follows: — 



The so-called isochromatic, or orthochromatic, sensitive 

 plates have been recommended for use in astronomical pho- 

 tography, in order to obtain impressions of red or yellow 

 stars along with those having more blue and violet light in 

 their radiations. Spectroscopic observations have shown 

 that the light of different stars differs very much in the pro- 

 portion of highly refrangible rays, and this difference must 

 be of great influence in determining their photographic ac- 

 tion. The ordinary sensitive gelatine plates possess a maxi- 

 mum of sensitiveness near the Fraunhofer line H, but some 



