August 5, 1922] 



NA TURE 



189 



direction-finding was carried out by Messrs. Kolster 

 and Dummore, and that the use of two horizontal 

 coils as a transmitter was due to Mr. Willoughby. 

 Mr. Breit's own work was confined to the calculation 

 of the radiation from the Willoughby transmitter. 



The Imperial Bureau of Mycology, in addition to 

 its other activities, has recently begun the publica- 

 tion, under the editorship of the director, Dr. E. J. 

 Butler, of the Review of Applied Mycology. One 

 of the important functions of the Bureau is the 

 accumulation and distribution of information on all 

 matters connected with the diseases of plants, and the 

 co-ordination of investigations in this particular 

 field of study to enable workers in all parts of the 

 world to keep in touch with recent research. In 

 order that this may be accomplished a complete 

 index of the literature is to be kept, and abstracts 

 of the more important investigations will be pub- 



lished. The review is being issued monthly and 

 several numbers have already appeared. The im- 

 portance of a periodical of this kind issued by a 

 competent authority is obvious, and if only the 

 abstracting can be maintained at its present high 

 level and the review published punctually, with 

 abstracts well up-to-date, it will be of great service 

 to economic mycologists. 



Major T. F. Chipp, Conservator of Forests, Gold 

 Coast, since 1921, and previously assistant director 

 of the Botanic Gardens, Singapore, has been appointed 

 assistant director of the Royal Botanic Gardens, Kew. 

 Major Chipp received part of his early training at 

 Kew and worked as a temporary technical assistant 

 in the Herbarium. Later he went as demonstrator 

 in botany at the Birkbeck College, and in 19 10 

 was appointed an assistant Conservator of Forests in 

 West Africa. 



Our Astronomical Column. 



Large Fireball on July_26. — The Toronto corre- 

 spondent of the Times, in a message dated July 

 26, reports that a loud explosion shook the ground 

 for 20 miles round Wynward, Saskatchewan, and 

 that a giant meteor was seen to fall into the Big 

 Quill Lake. A large fiery ball was observed by 

 many persons in the district to drop from the clear 

 sky, and after it had sunk in the waters of the lake, 

 clouds of steam are said to have risen from the 

 surface. 



Other reports have come from Vanscoy, south- 

 east of Saskatoon, which is in longitude 107^° west, 

 and north latitude 52^°. The inhabitants of this 

 neighbourhood heard five or six explosions, and the 

 ground lying between Vanscoy and Pike Lake was 

 severely shaken. 



No further details of a definite character have yet 

 been received, and it is difficult from the information 

 at hand to draw safe conclusions other than that a 

 large fireball descended near the places named, and 

 apparently fell to the earth. The date of July 25 

 or 26 is one when large meteors are usually abundant. 

 The principal shower is sometimes directed from 

 near the stars a x and a., Capricorni. The meteors 

 of this shower are often brilliant, and they traverse 

 long paths with slow motion. It is quite possible 

 that one of the objects composing this stream may 

 have ' fallen to the earth, and is identical with the 

 fireball observed. 



The System of Castor. — -This interesting system 

 has been the subject of much research since the 

 earliest known observation of it as a binary by 

 Bradley and Pound in 1719. The determination of 

 the period was nearly hopeless until comparatively 

 recently ; until 40 years ago some computers put 

 forward values so large as 1000 years. But with the 

 approach to periastron, which is due in some 30 

 years, the problem is simplified, and Mr. W. Rabe, 

 in an exhaustive study of the system in A sty. Nach., 

 No. 5164-5, gives the following elements : a=6"-o6, 

 e =o-5593. i=66°-79, w = 8i°-97, fi = 32°-55, T = 

 r 954"73> Period 306-28 years. The probable error of 

 the period is given as 5 years. The orbit coincides 

 practically with the minimum ellipse drawn by Air. 

 Lewis in Ins Memoir on the Struve double stars. 

 The analysis of the observations by Mr. Rabe supports 

 the suggestion, first vaguely made by Mr. Burnham 

 (Mon. Not. R.A.S., vol. 51), that the fainter star has 



. NO. 2753, VOL. I JO] 



a fairly close unseen companion, the period being about 

 8i- years. The spectroscopic observations of radial 

 velocity are stated to agree with this hypothesis. 

 The parallax of the system is discussed, and the 

 value o"-o745 adopted. The combined mass is then 

 5-74 in terms of the sun ; Rabe assigns 3-33 of this 

 to the brighter star, 2-41 to the fainter. If the 

 supposed unseen companion is real then its mass 

 accounts for o-6o of the 2-41. 



Both of the visible stars are spectroscopic binaries, 

 and from the velocities measured it had been con- 

 jectured that the fainter star was the more massive. 

 This, however, involved the doubtful assumption that 

 the spectroscopic orbits were coplanar with the prin- 

 cipal orbit, an assumption rendered improbable by 

 Mr. Rabe's discussion. As the distant companion C 

 is also a member of the system, there would seem to 

 be at least six components altogether. 



The proper motion of the centre of gravity could 

 not be given till the mass-ratio was determined. 

 Mr. Rabe gives it as -o s -oi34 in R.A., and -o"-io8 

 in Decl. Combining this with the radial velocity, 

 and correcting for solar motion, the true velocity is 

 10-46 km. /sec. towards R.A. 305°-5, Decl. +42°-5. 

 This agrees with the motion of a group of 22 A-stars 

 of Drift I discussed by Prof. Plummer. 



The Dominion Astrophysical Observatory, Vic- 

 toria. — Publication No. 26 of vol. i. of this observa- 

 tory contains a list of 88 new spectroscopic binaries 

 discovered there, in addition to the first 100 announced 

 in No. 10. The spectrograph is mounted on the 

 72-inch reflector which is used as a Cassegrain with 

 equivalent focal length 100 feet. Analysis of the 

 stars shows that they are distributed through all 

 spectral types, but 90 per cent, belong to types B, A 

 and F. Of the B-stars about every second one in- 

 vestigated proved to be binary, suggesting that 

 duplicity may be the normal accompaniment of the 

 attainment of this type, for in some cases the 

 variable velocity would not be detected if its com- 

 ponent in the line of sight was small. The following 

 star of the pair 2 iSqo (separation 3"-5) is one of the 

 stars on the list. The preceding star has a fixed 

 velocity, while the following one shows in the violet 

 " beautiful sharp double lines with a separation of 

 about 70 km." Another star is Boss 4777, which is 

 the distant companion (46") of /3 Lyrae. 



