May II, 1911] 



NATURE 



359 



systems. As the article is well illustrated and deals to 

 a large extent with installations less well known in this 

 country, it will prove of great value to those who wish to 

 ^■et a bird's-eye view of the present state of the problem' of 

 fkctrification of railways. Subsequent articles will deal 

 more in detail with the conditions under which electric 

 1 Taction is advantageous, and the relative merits of the 

 various systems. 



W'f. loarn from an illustrated article in The Engineer for 

 April 28 that the 9,000,000-gallon water tank, constructed 

 by Messrs. Clayton, Son and Co., of Leeds, for the water 

 supply of Calcutta, is now finished. This tank is 321 feet 

 square and is 16 feet in depth. The height from the top 

 of the tank to fjround I(^vel is no feet; the tank is sup- 

 ported by a large number of braced steel columns. The 

 lank is divided into four compartments by cross frames, 

 each of which can be used independently, so that one or 

 more compartments can be put out of service for cleaning 

 or repairs without interrupting the service from the others. 

 The tank is constructed of steel plates f inch in thickness 

 and is thoroughly stiffened. The tank is roofed in, the roof 

 overhanging the tank by 12 inches. Plates and brass wire 

 gauze are fitted in order to prevent birds, &c., from gaining 

 access to the tank. The tank had to be made absolutely 

 watertight by the terms of the contract, and this has been 

 carried out successfully. 



The Cambridge University Press has published 

 -•^parately, price 35., the exercises from Dr. C. Davison's 

 " Algebra for Secondary Schools," which was reviewed 

 in Natl'RE on November 19, 1908 (vol. Ixxix., p. 65). 



MESSRS. WiTiiERBV AND Co. have in the press and will 

 shortly publish an illustrated travel book, entitled 

 " Through South Westland," by Miss A. M. Moreland, 

 being a chronicle of a ride through a district in New 

 Zealand which is little known to the outside world. 



The latest ornithological catalogue of Messrs. John 

 Wheldon and Co., 38 Great Queen Street, London, W.C, 

 which has been received, is conveniently arranged under 

 countries. It includes particulars of the books from the 

 library of an eminent ornithologist lately deceased, and 

 selections from several other important libraries. The 

 catalogue gives details of 1450 books and papers. 



The Royal Insurance Company, Ltd., of Liverpool, has 

 I issued the eighth edition of " Records of Sports." Among 

 its new features may be mentioned the section dealing 

 witli aviation, wliii h provides full information, up to the 

 end of loio, of notable performances and other events in 

 connection with aviation. The details provided in connec- 

 tion with many sports have been greatly amplified. Copies 

 of this interesting book of reference rnay be obtained, so 

 long as the supply lasts, by applying to the manager of 

 the company at i North John Street, Liverpool. 



Erratum. — In the abstract of a paper read before the 

 Royal Society of Edinburgh, printed in Nature of April 6, 

 p. 200, second column, line 8 from bottom, the " in the 

 formula y"(x + a) was omitted. The formula was printed 

 exactly as it was in the type-written copy supplied by the 

 reporter, and the error was unfortunatdv not noticed by 

 him in proof. 



OUR ASTRONOMICAL COLUMN. 



AfF.TF.ORic FiREBAU.s AND Metf.ors. — On April 30, at 

 11.58 p.m., the Rev. T. E. R. Phillips, of Ashtead, Surrev, 

 saw a fine meteor about three times as brilliant as Jupiter. 

 It was directed from Virgo, and disappeared in 206°+ 14°, 

 only tile end course of alx>ut 3 degr'^es l)ping observed. 



NO. 2167, VOL. 86] 



On May 2, at 10.53, ^I*"- J- H- Elgie, of Leeds, saw 

 a fine meteor equal to Venus descending from 2° above 

 /3 Serpentis to 4° above /3 Librae. 



On May 4, at 8.52 p.m., Mr. S. A. Wilson, of Reigate, 

 Surrey, witnessed the flight of a magnificent meteor from 

 the Polar star to a few degrees below Capella. Its light 

 was estimated as three times the apparent lustre of Venus. 

 It left a long train in its wake, and moved with fairly 

 slow speed. The radiant point was probably in the eastern 

 sky at about 247° -1-2°, as there is a very active shower of 

 bright meteors from this point in May, and the direction of 

 the fireball of May 4 is nearly conformable with this 

 stream. 



Mr. F. T. Naish, of Bristol, watched the eastern sky 

 on May 4, i4h. to i5h., and saw eight fairly bright 

 meteors. Three of these were conspicuous from their 

 streaky trains and very long flights, and they were directed 

 from the radiant point of Halley's comet. The paths 

 intersected at 338° — 2°. The shower of Aquarids supposed 

 to be associated with the famous comet referred to has 

 certainly returned this year, though not in special abund- 

 ance according to the reports already received. 



The Total Eclipse of the Sun. — Major Hills, secretary 

 of the Joint Permanent Eclipse Committee, has, according 

 to The Times of May 5, received a telegram from Father 

 Cortie stating that thick cirrus clouds persisted at totality, 

 but photographs of the corona and spectrum were 

 obtained ; the corona was characteristic of the minimum 

 sun-spot period. 



A telegram received by the Astronomer Royal from Mr. 

 Worthington, who was also stationed at Vavau, reads : — 

 " Splendid photos, inner and outer corona, one and a half 

 degrees." 



A later communication states that Mr. C. L. Wragge, 

 formerly meteorologist to the Queensland Government, 

 saw the eclipse under excellent conditions at Lifuka, 

 Friendly Islands. Hydrogen prominences were wonderfully 

 distinct, and, apparently', a four-vaned corona was seen 

 extending some distance from the moon's disc. 



Spark Spectra ok Calcium and Hydrogen in a Mag- 

 netic Field. — Some results possibly of great importance 

 in the study of solar physics are published by M. Hemsa- 

 lech in the Comptes rendus for April 24 (vol. clii., No. 17, 

 p. 1086). 



M. Hemsalech finds that when a spark is passed per- 

 pendicularly to the lines of force in a strong magnetic 

 field, the enhanced lines in the spectrum of the spark 

 behave differently from the arc lines. When the spark 

 passes between calcium poles, in a field of from 4000 to 

 6000 C.G.S., it is violently projected in a sheaf at right 

 angles to the lines of force, and a spectroscopic examina- 

 tion of this sheaf shows that the line at A 4227 is as long 

 as H and K ; the spectroscope is pointed parallel to the 

 lines of force. When the spark is passed in a strong 

 transverse current of air, without a magnetic field, the 

 4227 line is much longer than H and K. 



But when the spark is passed, in the magnetic field, in 

 an atmosphere of hydrogen, a remarkable change takes 

 place, for whereas the respective heights of the H and K 

 lines were 22.6 and 23-7 cm., the 4227 line was only i6'3 

 cm. ; the heights of the hydrogen lines were Ha 2i-4. 

 H/3 200, H7 18-8, and H5 16-3 cm. The spark lines at 

 A 3706 and \ 3737. in the vicinity of the poles, are also 

 higher than the arc lines \ 4283 and \ 4455. In an atmo- 

 sphere of oxygen, however, the 4227 line is as long as 

 H and K, and if a weaker current, 800 C.G.S., is 

 employed, it becomes longer and stronger than they. 



M. Hemsalech tentatively suggests an analogy with the 

 solar conditions. A mass of hydrogen atoms carrying 

 electric charges, and travelling parallel to the solar surface, 

 might, in the magnetic field around a spot, become 

 violently projected, as in the laboratory, and carry wit|i 

 it to as great or a greater height the calcium vapour so 

 abundant in the solar atmosphere ; this could not happen 

 immediately over a spot nucleus, for there the lines of 

 fori o are perpendicular to the solar sm fat .\ 



i'riE Solar Constant. — Messrs. Abbot and F. E. Fowle, 

 jun.. discuss the value, during recent years, of the solar 

 constant of radiation in No. 3, vol. xxxiii., of Tlic Astro- 



