658 



NATURE 



[July 22, 1926 



the wear of the trolley wire is proportional to the 

 current collected. When no current is taken the wear 

 is almost negligibly small. A curious anomaly in 

 the treatment of railways with and without Parlia. 

 mentary powers was pointed out. The former rail- 

 ways are not allowed to have more than a 7-volt 

 drop on their rails, whilst the latter have sometimes 

 more than a loo-volt drop for short periods. It seems 

 to us that a careful search should be made in neigh- 

 bouring pipes, etc., for electrolytic damage in the 

 latter case. If the damage should prove to be in- 

 appreciable, then the limit of 7 volts might be raised 

 for all railways, as this would appreciably lower the 

 cost of electrification. 



Messrs. Newton and Wright, Ltd., desire it to 

 be known that their business will be carried on in 

 future from their works address, 471-77 Hornsey 

 Road, N.19, which is now the head office of the com- 

 pany. In furtherance of their policy of restricting 

 themselves to' a wholesale business, an arrangement 

 has been concluded with Messrs. Allen and Hanburys, 

 Ltd., by which this firm becomes selling agents in the 

 London area for Messrs. Newton and Wright, and 

 also in those parts of the United Kingdom where 

 the latter is not specially represented. Messrs. Allen 

 and Hanburys are taking over the electro- 

 medical showroom at 72 Wigmore Street, W.i, until 

 recently occupied by Messrs. Newton and Wright, 

 who will, however, have free access to these 

 showrooms, and one of their directors will always be 

 glad to meet country and other customers by appoint- 

 ment who may not have time to visit the head office 

 at Hornsey Road. The arrangements with Messrs. 

 Allen and Hanburys are so framed as not to preclude 

 Messrs. Newton and Wright doing business with 

 other trade houses, and the firm will be pleased to 

 continue supplying their specialities through whatever 

 trade house a customer may select. 



The special catalogues of Messrs. J. Wheldon and 

 Co., 38 Great Queen Street, W.C.2, are always of 

 interest and value, and the latest (New Series, No. 90) 

 is no exception. It is a well-edited, classified list of 

 upwards of 1200 books and pamphlets on ornithology. 

 The sections are British Islands, Europe, Asia, Africa, 

 North America, Central and South America, Aus- 

 tralasia, General Systems, etc., Economic Ornithology, 

 Miscellanea, and Morphology. Many scarce works 

 are included. In addition, particulars are given of 

 many complete sets or long runs of scientific journals. 

 The catalogue should be of service to purchasers of 

 books of science. 



Messrs. H. K. Lewis and Co., Ltd., 136 Gower 

 Street, W.C.i, have just circulated the quarterly 

 catalogue of new books and new editions added to 

 their Medical and Scientific Circulating Library 

 during the months April-June. It is a useful classified 

 list of the works in science published in the period 

 named, and should be found useful even to non- 

 subscribers to the library. Messrs. Lewis have also 

 issued a list of second-hand and surplus library books 

 an agriculture, botany, chemistry, engineering, geo- 

 logy, physics, zoology, etc. Many of the volumes 

 are offered for sale at greatly reduced prices. 

 NO. 2647, VOL. 105] 



Our Astronomical Column. 



A New Comet. — The second cometary discovery of 

 the year was made at Nice by M. Schaumasse on 

 July 18 at i3h. 37-im. G.M.T., in R.A. ih. 47m. 52s., 

 south decl. 1° 14', daily motion +2m. 24s., S. 5', 

 nth magnitude. 



The following" positions have been deduced on the 

 assumption of uniform motion : 



July 23 



28 



R.A. 

 h. m. s. 



1 59 43 



2 II 43 



The comet is a morning star, rising at i a.m. 

 summer time. It is not very far from Tempel's 

 comet, discovered at Kyoto at the end of May, but of 

 which no further observations have come to hand. 



Later.— M. Schaumasse now finds that his new comet 

 is identical with Tempel's second periodic comet, the 

 previous announcement by Mr. Kudara, of Kyoto, 

 being erroneous. The time of perihelion now becomes 

 1920 June 967, a month earlier than the time deduced 

 from Mr. Kudara 's announcement. 



The following is an approximate ephemeris for 

 Greenwich midnight : 



Log : 



Log A 



Publications of the Dominion Astrophysical 

 Observatory, Victoria, B.C., Vol. i.. No. i. — This 

 volume contains a full account of the inception of the 

 scheme of constructing the great 72-in. equatorial, and 

 demonstrates the immense amount of careful thought 

 and consultation of experts, both opticians and astro- 

 nomers, that preceded the adoption of the designs. 



Before the site was settled, Mr. W. E. Harper 

 tested the quality of seeing at a number of stations in 

 different parts of Canada, using a 4|-in. Cooke photo- 

 visual telescope. Victoria was finally selected, owing 

 to the excellent seeing at night, though there was less 

 sunshine than at Ottawa ; the small diurnal range 

 of temperature also favoured it. 



The glass discs were cast at St. Gobain, the optical 

 work was entrusted to the J. A. Brashear Co., and the 

 mechanical work and dome to the Warner and Swasey 

 Co. 



The ball-bearings, in dustproof cases, prove very 

 efficient, so that it is stated that when the clock is 

 disconnected a 35-lb. weight on a 26-ft. arm sufifices 

 to set the telescope in motion ; a 400-lb. weight is 

 found sufficient for the driving clock, which is wound 

 automatically by an electric motor. The volume con- 

 tains details of the zonal tests applied to the mirror, 

 the results being very satisfactory. Temperature in- 

 sulation, consisting of cotton-felt, is used round the 

 mirror, and with the small temperature changes that 

 take place at Victoria the definition will never be 

 appreciably affected by this cause. 



The comfort and convenience of the observers are 

 studied, all the movements being carried out elec- 

 trically. Details are also given of the powerful 

 spectrograph, which is surrounded by a temperature- 

 case. It is possible to use the instrument visually 

 without removing the spectrograph, the image being 

 displaced laterally by reflecting prisms. 



Numerous large-scale photographs of the various; 

 parts make it easy to follow the description-s.. 



