January, 1913. 



KNOWLEDGE. 



17 



the publication of the guide that there is with regard 

 to the chronological arrangement of the specimens 

 in the museum. 



It is also apparent that the writer of the guide has 

 some relatives who are oculists and opticians, who 

 will certainly have to be consulted by anyone trying 

 to read the pamphlet carefully. 



On the title page we are told to "Notice" — "This 

 catalogue and guide are copyright, and immediate 

 proceedings in Chancery will be taken against any 

 infringers thereof." As our old friend Pooh- 

 Bah, F.L.A., would say, the punishment would 

 certainly fit the crime. 



The guide is a fair model of what a guide 

 should not be. It is badly printed, with ancient 

 type, on poor paper. The details of the cases are 

 mixed up with the history of the Palace, and with a 

 catalogue of the pictures, and there is no index ; so 

 that it is really a difficult matter to find anything in 

 it. Many of the cases are not numbered at all, and 

 we read of Case No. (long), Case No. (side), Case No. 

 (centre), Case No. (side long), and so on. By the 

 words side, centre, side long, and so on, I presume 

 reference is made to the position of the various cases 

 in their respective rooms, but as I was unsuccessful 

 in identifying them, I cannot confirm this suppo- 

 sition. 



An idea of the " scheme of classification " can be 

 obtained from the following particulars of the first 

 few cases, in which, if anywhere, an attempt at 



order has been made: — Case 1, Stone Ages, Bronze 

 Age, late Celtic Period ; Case 2, Ceramic Art. 

 Case 3 (no heading at all ! but apparently con- 

 tains objects of the first to fifth century A.D.) 

 Case 3, "continued"! Saxon Period; then follow 

 " Relapse to Barbarism " (sic) ; Case 4, Early 

 Mediaeval Pottery; Case 5, Battle Axes, Swords, etc.; 

 Case 6, Wine Bottles ; Case 7, Lighting Appliances ; 

 Case 8, Prehistoric Mammalia, etc. (the "etc." in- 

 cludes all sorts of things that ought to be miles away). 

 Next is a " Green Coloured Bust ' (sic), which sounds 

 rather like a bilious attack ! and a " Bell in case." 

 Then Case 9, Mediaeval London, and so on to Case 

 12. A description follows of the " Queen's Closet " 

 and " Pictures of Old London," followed by " Nos. 

 20 to 34," which are apparently pictures. After all 

 this, oddly enough, is a heading in large type, 

 " London Museum Exhibits," and it calmly proceeds 

 to a list of the contents of Case 13. And the guide 

 ends up with " A condemned Cell, Old Roman 

 Galley, Mantelpieces, etc. ; Panoramic Models of 

 Old London, Lobby for various exhibits, Old 

 Jacobean Room." It was with some such expression 

 as " A condemned Cell " that I closed the " Guide," 

 and thought of what might have been done with the 

 shilling. However, I will not say it is useless ; when 

 folded round, and fitted with a pill-box lid on the 

 top, it makes an excellent toy letter-box or money- 

 box, coloured red, and with G.R. on it already 

 complete ! 



NOTES. 



ASTRONOMY. 



By A. C. D. Crommelin, B.A., D.Sc., F.R.A.S. 



OBITUARY. — The deaths of two well-known English 

 astronomers have occurred recently. Sir George Darwin, the 

 Plumian Professor, had been in failing health for some time, 

 though he was able to read in person his last paper (on a new 

 form of periodic orbit) to the Astronomical Society last 

 summer. His principal work was on the theory of the tides, 

 and their secular effects on the development of our system. 

 He was the originator of the view (still, I think, held by most 

 astronomers, though there are some important dissentients) 

 that the moon was formed by tidal disruption of the earth by 

 solar tides at a time when the rotation was very rapid, and 

 that the moon has acted as a brake on the earth ever since, 

 bringing the rotation to its present value, while the reaction 

 on the moon has caused its recession. He was the author of 

 a very useful popular treatise on the tides, which explains 

 the method of Harmonic Analysis, and shows how the tides 

 may be predicted for any port after a sufficiently long series 

 of records is available. His work on periodic orbits was an 

 investigation of the different paths a small planet might follow 

 under the action of the Sun and an imaginary large planet, 

 Jove, whose mass was one-tenth of the Sun's. This list of 

 his works only includes those portions which are of most 

 interest to non-specialists. 



The death of Mr. S. A. Saunder, the Gresham lecturer, was 

 far more unexpected. He was taken ill during his course of 

 lectures on the Tides last October, but managed with difficulty 

 to finish them. Many of our readers must have heard his 

 lucid explanations of some rather difficult branches of 

 astronomy. He was a Vice-President of the Royal Astro- 



nomical Society, and it was expected that he would before 

 long fill the Presidential chair. The astronomical work for 

 which he will be chiefly remembered was the accurate deter- 

 mination of the positions of a large number of points on the 

 moon, using the beautiful large-scale photographs taken at 

 Paris and in America. He found that the previously assumed 

 positions were much in error ; they had been made by measures 

 at the telescope from the limb ; he showed that it was far 

 better to get them from measures on the photographs, 

 provisional coordinates being first assumed for some leading 

 points, which could be afterwards checked and corrected by 

 the results. Accurate places of several thousands of points 

 were thus found, and by comparing their positions in different 

 librations it was possible to say which regions of the moon 

 were above the general level and which below it. He showed 

 that this was as difficult as finding the parallaxes of the 

 nearer stars. He was superintending the preparation of a 

 large map, on which the points measured by him were accurately 

 laid down, and the filling in of detail done from the photographs. 

 Mr. J. A. Hardcastle was associated with him in some of his 

 work, and gave much help in the measures. 



THE ALBEDOES AND BRIGHTNESS OF THE 

 PLANETS. — Some photometric observations of the stellar 

 magnitude and albedo of the planets have been made with 

 the Draper Telescope at Harvard College Observatory. The 

 result for Venus at mean superior conjunction was — 2 m -56 

 (thirty-four exposures on twenty-eight plates). The following 

 magnitudes are for mean opposition : — Mars, — m -57 (thirty- 

 seven exposures on thirty-six plates) ; Jupiter, — l m - 78 (twenty 

 exposures, nineteen plates); Saturn, +l m -52 (twelve plates). 

 The differences, photographic magnitude minus Muller's photo- 

 metric magnitude, are: — Venus, 4-l m -08; Mars, + l m -33; 



