282 



NA TURE 



[July 19, 1906 



OVR ASTRONOMICAL COLUMN. 

 Rediscovery of Finlay's Comet (igoSd). — A telegram 

 from the Kiel Centralstelle announces the rediscovery of 

 Finlay's comet by Herr Kopf on July i6. The position 

 of the comet at i3h, 14-401. (Konigstuhl M.T.) on that 

 dale was : — 



R.A. = 23h. 38-3m., dec. = 14° 3' S. 



The object is stated to be a bright one. Subjoined is 



an extract from the approximate ephemeris published by 



Herr .Schulhof in No. 4100 of the Astronomische 



Nachrichten : — 



12 7;. M.T. Paris. 



1906 

 July 16 



.(.rue) 



4 (truel 



23 44 ... - 13 7 ■■■ 9"544.'; 

 - 2: 57 .. - 12 10 . . 9-5254 



20 Oil ... - II 6 ... 9 5073 



22 .0 25 ... - 9 56 ... 94902 



24 ... o 40 ... - 8 40 ... 9 '4744 



26 o .;6 .. - 7 17 ... 9-4602 



28 1 13 ... - 5 47 9-4478 



30 I 30 •■• - 4 12 ... 94.^76 



Auc- I I 47 ■•■ - 2 33 ... 9-4299 



A comparison of the observed and computed places on 

 July 16 will give an approximate value for the corrections 

 to be applied to the ephemeris positions. When redis- 

 covered, the comet was about one degree north of 

 u> .'\quarii ; at present (July 19) it is presumably about five 

 degrees north of 2 Ceti, and is travelling in a north- 

 easterly direction, so that it now rises above the south- 

 east horizon at about 11.30 p.m. 



The Orbit of Castor. — An interesting paper on the 

 quadruple system of Castor, by Dr. H. D. Curtis, appears 

 in No. 5, vol. xxiii., of the .islropliysical Journal. 



The discussion is based on the results obtained from a 

 number of spectrograms, of each of the two double systems, 

 taken with the Mills spectrograph at the Lick Observatory. 

 For the fainter component, a,, of the visual system, the 

 final elements deduced give the period as 2928285 days, 

 the eccentricity as o-oi +00066, and the velocity of the 

 system as — o-98 + oi5 km. The comparison of these 

 elements with the observational results shows a satisfactory 

 agreement. Reducing the observational results for the 

 brighter component, a,. Dr. Curtis obtained a final set of 

 elernents which give the period as 9-218826 days, the eccen- 

 tricity as 0-5033 + 0-0II2, and the velocity of the system as 

 -1-6-20 + 0-17 km. 



Combining these results with those obtained for the 

 visual system, it should become possible to obtain values 

 for the parallax, masses, and other physical constants of 

 this remarkable quadruple system, but the visual results, 

 as shown in a table given by Dr. Curtis, are as yet so 

 indeterminate that any values so obtained could not be 

 looked upon as being in any way final. The relative 

 velocity of the two components as derived from Dr. Curtis's 

 discussion is 7-14 + 0-23 km., and, taking Prof. Doberck's 

 period of 347 years for the visual system, this would 

 indicate a parallax of o"-o5. On a similar assumption the 

 semi-major axes of the two systems are as follow : — 



a, Geminorum, a = 1,435.000 km. 

 Oo ,, = 1,667,000 ., 



.■\lthough these results are mere hypotheses, they give 

 some idea of the magnitude of each system, and show that 

 they are probably of about the same dimensions. 



Planets and Planetary Observations. — In the first of 

 a series of articles on " Planets and Planetary Observ- 

 ation " which he is contributing to the Observatory, Mr. 

 Denning discusses the general problems to be attacked 

 and also the instrumental equipment necessary for the work. 

 After discussing the relative merits of refractors and re- 

 flectors, he points out that no amateur observer should be 

 discouraged because he possesses only a relatively small 

 instrument, and states that none of the largest telescopes 

 yet employed in this branch of astronomy shows anvthing 

 beyond what is readily distinguishable in an 8-inch glass. 

 NO I 9 16, VOL. 74] 



T//£ SANITARY CONGRESS AT BRISTOL. 



"T^HE twenty-third Congress of the Royal Sanitary Insti- 

 tute was held at Bristol during the week ending 

 July 14. Sir Edward Fry presided. The proceedings of 

 the congress comprised the usual general meetings ; meet- 

 ings in three sections, (i) sanitary science and preventive 

 medicine, (2) engineering and architecture, (3) physics, 

 chemistry, and biology ; and meetings of conferences of 

 various classes of persons interested in sanitary science. 

 This year there were conferences of municipal represent- 

 atives, under the presidency of Councillor Colston VVintle, 

 chairman of the health committee of the City of Bristol, 

 who took a prominent part in the proceedings of the con- 

 gress ; of medical officers of health, under Dr. D. S. Davies, 

 medical officer of health, Bristol ; of engineers and surveyors 

 to county and other sanitary authorities, under Mr. H. 

 Percy Boulnois, of the Local Government Board ; of 

 veterinary inspectors, under Mr. Frank Leigh ; of sanitary 

 inspectors, under Mr. \. E. Hudson, chief sanitary in- 

 spector, Cheltenham ; of women on hygiene, under Miss 

 Mary Clifford, in the absence of the Duchess of Beaufort ; 

 and also a conference on the hygiene of school life, under 

 the presidency of the Bishop of Hereford. 



In the presidential address to the congress on Monday, 

 July 9, .Sir Edward Fry dealt clearly and concisely with 

 the general history of sanitary works and the regulation of 

 public health. After pointing out the increase of duties and 

 responsibilities which had devolved upon the heads of 

 modern households and upon local authorities in conse- 

 quence of the recent developments of sanitary science, he 

 referred in turn to the sanitary ordinances of the Greeks, 

 the Jews, and the Romans up to the disappearance of all 

 thought of sanitary science in the ruin of the Western 

 Empire. Finally, he referred to the legislation on the sub- 

 ject in Great Britain since the middle of last century. 



Sir W. J. Collins, president of Section L, sanitary science 

 and preventive medicine, was detained in London by urgent 

 parliamentary duties, and the address was read by Dr. 

 Shingleton Smith. It protested against the too exclusive 

 consideration of bacteriology, and appealed for greater 

 attention to be paid to the soil in which bacteria are 

 implanted, and upon which they depend for their develop- 

 ment. In .Section II., engineering and architecture, the 

 president, Mr. Edwin T. Hall, referred to a number of 

 points in which the architect could assist the promotion of 

 sanitation by the design of buildings. Dr. W. N. Shaw, 

 president of Section III., physics, chemistry, and biology, 

 took for his subject climate and health. After referring to 

 the work of Sir Arthur Mitchell, Dr. Buchan, and Dr. 

 Longstaff, he indicated the climatological material available 

 for the study of questions upon the relation of health to 

 climate, and discussed the methods of using it. In the 

 course of the address he showed a meteorological .section 

 of the British Isles from north to south, Sumburgh Head 

 to Hastings, and another from west to east, Valencia to 

 Margate. He also exhibited some interesting diagrams of 

 the average diurnal variation of relative humidity for certain 

 selected months at four observatories in the United 

 Kingdoin, and some autographic records of the same 

 element at Cambridge, showing remarkable fluctuations of 

 humidity within the period of twenty-four hours. 



The subjects of the addresses at the various conferences 

 and of the papers and discussions were for the most part 

 of a technical character. Questions concerning milk supply 

 and its regulation were raised in Section I. by Dr. J. 

 Fortescue-Brickdale and by Mrs. C. Hamcr Jackson, at 

 the conference of medical officers of health by Prof. H. 

 Kenwood, and at the conference of veterinarv inspectors 

 by Dr. W. G. Savage and by Mr. J. S. Lloyd.' The ques- 

 tion of dust, particularly of motor dust, also came up in 

 various forms. In the conference of engineers it was raised 

 by a paper by Mr. A. P. I. Cotterell, and in Section III. 

 the influence of dust on health was a subject of discussion 

 opened by Dr. P. Boobbyer. Of the suggestions made for 

 dealing with the question, some of them could only be 

 called fantastic. The discussion of various aspects of the 

 bacterial treatment of sewage also found a place in several 

 sections or conferences. The necessilv for the extension of 



