■144 



KNOWLEDGE. 



November, 1910. 



THE ASTROGKAPHIC SURVEY. 

 To the Editors of '" Knowi.ei.ige." 



Sirs, — A sentence on p. J99, referring to this work, is 

 liable to misinterpretation. A share of one thousand one 

 hundred and eighty plates, equal to more than one-twentieth, 

 in this International Survey was undertal;en at the University 

 Observatory at O.xford. The worl< was commenced and 

 the first plates were talcen in 1892, and it was then under- 

 stood that twenty-five years would be required to complete 

 it. All tlie plates were talcen, completely measured, reductions 

 made, and the measures of about four hundred thousand star 

 places were copied for printing by 1904, February 17th; this 

 would have been accomplished from one to two years earlier but 

 for interruptions and loss of time due to a new dome being 

 built, during which no progress could be made with the 

 telescopic work ; to the planet Eros work ; and to a struggle of 

 some months with bad emulsion on the plates. Looking up 

 the Greenwich Observatory reports, I find that in l')0(), 

 February, their share of the survey, one thousand one hundred 

 and forty-nine plates, was still unaccomplished : at the present 

 moment none of the other sixteen observatories, with one or 

 two exceptions, are near the end of their shares; in some 

 cases the measurement of the plates has barely commenced, 

 and all the negatives required are not yet taken. The 

 University Observatory at Oxford liad thus comiileted its share 

 of the Catalogue two years or umii' befnre that at the Royal 

 Obser\'atory. 



These remarks refer to the main portion of the schenie .lud 

 by far the most important. As to the supplementary portion, 

 repeating the work by exposures of forty minutes on separate 

 plates for the purpose of reproduction only as star-maps, it 

 became apparent soon after the commencement of the work 

 in 1S92 that it would be a waste of time, energy and money to 

 carry out this portion. The reasons for the decision not 

 to do the Chart portion at Oxford were the supercession, or 

 doubtful need, of the 1887 and 1889 programmes relating to 

 the Chart scheme, by the advent of the doublet form of photo- 

 graphic lenses of large dimensions (such as the Bruce lens at 

 the Areguipa Observatory, with which it is easy to photograph 

 about five-and-a-half plate areas on each 17X14 plate and 

 with less exposure to obtain the same limit of magnitude), so 

 that the whole of the Oxford area could be covered by less 



than two hundred plates instead of one thousand one hundred 

 and eighty plates and with much less risk of having to reject 

 plates by reason of cloud interference ; another reason was the 

 impossibility of obtaining the /. 10,000 required to reproduce 

 and distribute tlie maps on the same luxuriant scale as those 

 published by aid of the French Government, and the inadvisa- 

 bility of spending such a sum ; and a third reason, which 

 I see is referred to by your correspondent on page 409, 

 may be considered as a strong point — the enlarged reproduc- 

 tion of the long-exposure chart plates. Had the prints 

 been kept to the same si^e or scale as the catalogue 

 plates, it would have been a very simple process to have 

 utilised the numerous measuring instruments already avail- 

 able for the measurement of positions if required ; that 

 this can be done with a considerable degree of accuracy 

 was pointed out in the Mo/if /i/j' A'of/ct's by Professor Turner 

 more than twelve years ago. Thus has the Oxford area for 

 long exposed plates been "in the field" since 1895 ; it is only 

 this portion of the survey which the Greenwich Observatory 

 has appropriated : that the short exposure plates are also to 

 be taken at this near epoch appears to me to be indicative of 

 waste and annoyance. 



Notwithstanding all eftbrts to obtain the money, the printing 

 could not be commenced until 1906, so that no progress could 

 be made in this direction during the progress of the other 

 stages of the work. Since that date the amount printed has 

 been such that six volumes have been published and distributed, 

 and the seventh — the last of the catalogue — is almost 

 completed, the whole giving accurate measures of more than 

 four hundred and fifty thousand star positions contained, 

 besides other information, on two thousand three hundred 

 quarto pages. No assistance for the main share — the cata- 

 logue — has been given by the Royal Observatory to Oxford 

 as the words on page 399 would seem, to one unacquainted 

 with details of the scheme, to imply. 



It should be added that Prof. E. C. Pickering's suggestion 

 in 1886 to use a large double lens for the Chart portion was 

 rejected by the Astrographic Congress at Paris — probably no 

 one except himself then realized its great advantage for such 

 work as charting the stars; by the generosity of Miss Bruce 

 he was able to accjuire such a telescope of 24-in aperture 

 in 1893. 



F. A. BELLAMY. 



L I T V. R A R \' NOTICES. 



THh: CHARACTIIRISTICS OF FAMOUS Ml':\.— In a 

 work shortly to be published by Messrs. Rebnian — "' Makers 

 of Man": A Study of Human Initiative, by Charles J. 

 Whitby, M.I). — the problem of indi\'iduality is investigated by 

 means of an analytical study of forty world famous men. 

 The book is not a series of biographies — the lives are treated 

 collectively with a \iew to the attainment of general results. 



LICHEN EXCHANGE CLUB.— The annual report shows 

 that this club is doing a considerable amount of useful work, 

 in the way of distributing specimens, on the part of eighteen 

 out of the twenty-nine members. The report quotes the 

 sx'stematic arrangement of the class of lichens which is used 

 in the recent memoir of the United States Herbarium. The 

 Secretary and Treasurer, Mr. A. R. Horwood, of Leicester 

 Corporation Museum, appeals for information with regard to 

 species which are likely to become exterminated. 



THE BACILLUS OF LONG LIFE.— Messrs. T. C. and 

 E. C. Jack announce that they will pviblish in November, 

 under the above title, a manual of the soured milk industry, by 

 Loudon M. Douglas, F.R.S.E. 



HOUSE FLIES AND PUBLIC HEALTH.— A valuable 

 leaflet has been issued on the dangers resulting from house 

 flies and the preventive methods to be employed. Copies may 

 be obtained free on forwarding a stamped addressed envelope 

 to Walter E. Collinge, 59, Newhall Street, Birmingh.im. 



THE MICR(.)LOGIST. — The second part of a new 

 magazine called Tlie Micrologist has reached us. It is 

 published quarterly by Messrs. Flatters, Milborne and 

 McKechnie, Ltd,, at a price of eighteenpence. The paper 

 contains useful hints to the microscopist, and there is a very 

 good collotype plate of starch grains, Volvox, Hydra, and of 

 Polyzoa. 



THE ISIKLIOGRAI'HY OF AERONAUTICS.— 

 Aeronautics has for years past been universally indebted to 

 the Smithsonian Institute of America for its research work in 

 this new science, and for the clear and concise manner in 

 which it has always published the results of its labours. 



To-day, in The Bibliography of Aeronautics, we have 

 another work from the same source, compiled with similar 

 care, and « onderful completeness. 



In this book we have a complete index to every article of 

 the least \ alue in any language which has been published, and 

 to find any such article we have merely to look under the 

 author's name, when the title of the paper or manuscript in 

 which it appears will be given. 



As a test the writer looked up certain small articles, and in 

 every case found the proper references as above. 



Everything is indexed under "Authors' Names"; may we 

 some day hope to see the sister volume, in which the articles 

 will be indexed under " Subject Matter" ? 



