256 



NA TURE 



[August iq, 1922 



Speculations on the construction of the universe had 

 been made before Herschel's time : by Thomas Wright 

 in 1750. by an anonymous writer in 1755 (who after- 

 wards turned out to be Immanuel Kant, and adopted 

 most of Wright's conclusions), by Lambert, and by 

 Michell. None of these writers had made any observa- 

 tions on which to found their theories. But Herschel 

 would build on observed facts so far as possible. He 

 began by attempting to find the distance of the fixed 

 stars by measuring double stars. This turned out to 

 be impossible; but the work done was not wasted, as 

 hundreds of double stars had been found and measured. 

 When many of these measures were repeated some 

 twenty years later, the great discovery was made that 

 not a few of these pairs of stars were revolving round 

 their common centre of gravity. The nebula; and 

 clusters of stars were next systematically searched for ; 

 2500 were found and their places determined. Herschel 

 started with the idea that all nebulas were composed 

 of stars, and he therefore included clusters, even rather 

 scattered ones, in his observations, as representing 

 with dense clusters and nebulae the different stages of 

 the same class of bodies. But the discovery of some 

 indubitably nebulous stars, or stars with atmospheres, 

 made him recognise that there must be here and there 

 in space some kind of " shining fluid " of which diffused 

 nebulas and planetary nebulae were formed. This idea 

 found very little favour among astronomers for many 

 years, particularly after the completion of Lord Rosse's 

 6-foot reflector, the maker of which was inclined to 

 think every nebula " resolvable." Yet Herschel was 

 found to be right when Huggins proved many nebulae 

 to have a gaseous spectrum. 



Another discovery of Herschel's, which was doubted 

 or denied until confirmed elsewhere, was the proper 

 motion of the sun through space. Here there was 

 perhaps some excuse for the doubters, as the material 

 available for the investigation was rather scanty. 



In order to get some idea of the distribution of the 



stars Herschel for some years took observations of the 

 star-density in various parts of the sky by counting 

 the stars seen in the field of his telescope. Making 

 two assumptions — that his telescope could reach the 

 boundaries of the Milky Way, and that the stars of the 

 system were tolerably uniformly distributed — he was 

 able to construct a rough diagram of the shape of the 

 -Milky Way svstem to which our sun belongs. This 

 is the well-known disc or grindstone theory, according to 

 which the stars are scattered between two planes, 

 roughly parallel to the belt of the visible Milky Way, 

 with a stratum running out to one side to represent 

 the bifurcation from Cygnus to Scorpio. Near the 

 centre of this system (also spoken of as " our nebula ") 

 Herschel placed our sun. In after years, in two papers 

 of 1817 and 1818, Herschel, as a result of his observa- 

 tions, was obliged to abandon the idea of uniform 

 distribution, and also to recognise that his telescope 

 could not reach the boundaries of the Milky Way 

 system. But that the system extended very much 

 further in the plane of the Milky Way than at right 

 angles to it, remained his opinion, though the concep- 

 tion of the system being a nebula — that is, a star cluster 

 — had been given up. 



Here again there was, towards the end of the 

 nineteenth century, a tendency to abandon Herschel's 

 results, and the opinion was set forth in more than one 

 quarter, that the Milky Way is really what it looks like — 

 a huge ring-shaped cluster. It has even been suggested 

 that it is a gigantic spiral nebula inside which our .sun 

 is situated — at first sight a rather tempting proposal. 

 But recent researches by Shapley have shown these 

 hypotheses to be untenable ; and his work on the 

 distribution of globular clusters, showing the enormous 

 distances of many thousands of light-years which 

 separate them from us, agrees in a remarkable manner 

 with the ideas worked out by the old astronomer at 

 Slough exactly a hundred years earlier, in the last 

 paper he sent to the Royal Society. J. L. E. D. 



Obituary. 



Dr. Arthur Ransome, F.R.S. 



THE death of Dr. Ransome at Bournemouth in his 

 eighty - ninth year recalls the memory of a 

 Manchester physician who was a pioneer in the training 

 of female health visitors, and in the investigation of 

 tuberculosis and of the cyclical waves of epidemic 

 diseases. He died on July 25 ; and by a striking coin- 

 cidence, at the first meeting earlier in the same day of 

 Section I. — that of Preventive Medicine — of the Con- 

 gress of the Royal Sanitary Institute then being held 

 in Bournemouth, a message of appreciation of Dr. 

 Ransome's past work had been authorised, which never 

 reached him. 



Dr. Ransome was born in Manchester in 1834. He 

 became an honorary fellow of Gonville and Caius 

 College, Cambridge, and for many years was consulting 

 physician of the Manchester Hospital for Consumption, 

 as well as Professor of Hygiene and Public Health at 

 Owen's College, 1880-95. 



Dr. Ransome's chief writings related to tuberculosis, 

 on which he published several books, as well as special 



NO. 2755, VOL. I io] 



contributions to the Epidemiological and other 

 Societies. He gave the Milroy lectures to the Royal 

 College of Physicians on the causes of phthisis, and 

 received the Parkes Weber prize for special researches 

 on tuberculosis. From his experiments he concluded 

 that finely divided tuberculous matter is rapidly 

 deprived of virulence in daylight and in free currents 

 of air ; that even in the dark, fresh air has some, 

 though a retarded disinfecting influence, and that in 

 the absence of currents of air the tubercle bacillus 

 retains its infectivity for long periods of time. The 

 general effect of his work was to emphasise the import- 

 ance of disinfection of rooms occupied by tuberculous 

 patients. At the same time Dr. Ransome attached 

 greater importance to sanitary and social improve- 

 ments in the prevention of tuberculosis than to direct 

 attack on the bacillus. 



In epidemiology Dr. Ransome was one of the first to 

 investigate the influence of cyclical waves in producing 

 the intermittent prevalence of epidemic diseases, 

 apparently independent of the accumulation of un- 

 protected persons. The Swedish tables of mortality, 



