October 30, 1919] 



NATURE 



179 



have been universally adopted in this, country, and 

 they are annually amended so as to keep them abreast 

 of the latest practice. The amendments this year are 

 almost of revolutionary importance. As we fore- 

 shadowed some months ago, the electricians have now 

 abandoned measuring the size of wires in terms of 

 the standard wire gauge (S.W.G.). They have 

 dropped gauges altogether. Instead of speaking of 

 a No. 20 wire, they speak of a 0036 wire — that is, one 

 having a diameter of 0036 of an inch. Similarly, 

 instead of writing 3/20 for a cable consisting of three 

 strands of No. 20 wire, they write 3/0036". Formerly 

 they had a choice of fifty-seven cables for use in elec- 

 tric wiring, but now there are only twenty-four sizes. 

 Careful consideration has shown that this number is 

 sufficient. Naturallv this will be a great boon to the 

 cable manufacturers. The British Engineering 

 Standards Association (the B.E.S.A.) is to be con- 

 gratulated on having initiated this important reform. 



For more than forty years the Institution of Civil 

 Engineers has printed' in its Proceedings short ab- 

 stracts of papers on engineering subjects which have 

 appeared in periodicals and in the Transactions of 

 scientific and technical societies. The institution now 

 proposes to issue them separately in quarterly 

 numbers, the first of which appears this month. 

 Although its length is affected by the difficulty of 

 obtaining periodicals from abroad, the first number 

 gives ninetv-nine abstracts, which cover seventv pages. 

 Subject- and name-indexes are provided, and it is much 

 to be desired that these should be made more useful 

 by co-ordination in annual or two-ye&rly indexes. The 

 abstracts are grouped under two heads : — Materials, 

 Measurements, etc., and Engineering Practice. As 

 the latter term is interpreted generously, there is some 

 overlapping with abstracts issued by other bodies, 

 and some svstem of interchange of abstracts will have 

 to be evolved to prevent several abstracts of the same 

 paper being written. 



At Universitv College, London, on October 21, a 

 public lecture was given by Prof. J. A. Fleming 

 entitled "Sneaking Across the .Atlantic by Wireless 

 Telephonv." Prof. Fleming opened by giving a 

 general review of the physical facts leading up to 

 ordinary telephonv, and the application of Fourier's 

 theorem to wave-forms, with their consequent resolu- 

 tion into harmonics, and the distortion produced in 

 ordinarv speech, due to the different velocities and 

 damping of the various harmonics. Since the electro- 

 magnetic waves emploved in wireless telegraphy have 

 a velocitv which is independent of the wave-length, 

 and a fa!ling-orf of intensity with distance which is 

 the same for all frequencies, there is no distortionof 

 the sound in wireless telephony similar to that which 

 occurs in long-distance telephony of the ordinary kind. 

 Speech transmitted bv wireless is particularly clear 

 and distinct. The three typical modes of producing 

 electromagnetic waves were explained and illustrated 

 by lantern-slides— the high-frequency alternator, the 

 Poulsen arc, and the three-electrode thermionic valve 

 used as generator. Prof. Fleming explained the mode 

 of action of the Fleming valve as a rectifier, and 

 the development of the three-electrode valve from this. 

 The Marconi Co. now uses seven such valves in cas- 

 cade for amplifving in receiving the feeble trans- 

 Atlantic speech," since the amplification increases 

 geometricallv with the number of valves used. By a 

 series of trials the Marconi Co. has demonstrated the 

 possibilitv of soeech over 1800 miles across the 

 Atlantic,' and, moreover, the trials were carried out 

 at an unfavourable time of day, 10 a.m. to i p.m. 

 The audience was large and appreciative, one of the 

 larger lecture-theatres of the college being required. 



NO. 2609, VOL. 104] 



A course of six lectures on "Thermionic Valves" is 

 to follow on succeeding Wednesdays at 5 p.m. 



Messrs. Chapman and Hall, Ltd., announce : — 

 "Aeronautical Engines," Major A. G. Clark; 

 "Theory and Practice of Aeroplane besign," S. T. G. 

 Andrews and S. F. Benson ; " Geometry for Architects 

 and Builders," J. E. Paynter; "Mathematics for 

 Engineers," W. N. Rose, vol. ii. ; and " Metric System 

 for Engineers," C. B. Clapham. Mr. W. Heine- 

 mann is to publish this autumn Sir Ernest Shackle- 

 ton's new book. It will be entitled "South: The 

 Story of Shackleton's Last Expedition, 1914-1917." 

 Messrs. G. Routledge and Sons, Ltd., promise 

 "Bakery Machinery," A. W. Mathys; "The Utilisa- 

 tion of Natural Powers," E. L. Burne ; " Engineering 

 Instruments and Meters," E. A. Griftiths; "Direct- 

 current Dynamos and Motors," Prof. W. B. Griffith; 

 and " Manufacture and Installation of Electric 

 Cables," C. J. Beaver (in the Industrial Supremacy 

 Books Series). In their Efliciency Books they will 

 publish " Bibliography of Industrial Efficiency and 

 Factory Management," H. G. T. Cannons, and a 

 new edition of " Lectures on Industrial Psychology," 

 B. Muscio. Messrs. H. Sotheran and Co. will shortly 

 issue an Illustrated Library edition of their " Biblio- 

 theca Chemico-Mathematica." It will contain many 

 full-page plates, reproductions of title-pages, textual 

 passages from rare or historically important works, 

 and an analytical subject-index. 



The special catalogues of Messrs. H. Sotheran and 

 Co. (140 Strand, W.C.2) are models of what cata- 

 logues of second-hand books should be, for they fur- 

 nish in an interesting manner much out-of-the-way 

 information respecting many of the volumes offered 

 for sale, and are carefully classified. Messrs. 

 Sotheran's latest catalogue (No. 773, 2S. 6d. net) deals 

 with rare books on exact and applied science, and 

 includes the library of the late Prof. Henrici and a 

 portion of that of Prof. G. Govi, of the University 

 of Naples. Its 3336 items are classified under the 

 headings : General and Collected Works ; Mathe- 

 matics ; .Astronomy and Geodesy ; Dialling and Horo- 

 logy ; Physics ; The Microscope and Microscopy ; 

 Meteorology and Physical Geography ; Chemistry ; 

 Crvstallography ; Chemical Technology, including 

 Photography ; Mining and Metallurgy ; Engineering ; 

 Seamanship, Airmanship, and Naval Architecture ; 

 and sets of Learned Societies' Publications and other 

 scientific journals. The catalogue will be very useful 

 for reference. 



OUR ASTRONOMICAL COLUMN. 

 Large Meteors. — On October 21, at 8h. 3sm. 

 G.M.T., a meteor brighter than Jupiter was observed 

 by Mrs. Wilson at Totteridge, by Mr. C. P. Adam- 

 son at Wimborne, and by Mr! H. G. Baker at 

 Wangford. It was directed from a radiant near 

 oCephei, and moved slowly at an average height in 

 the atmosphere. On October 22 at 7h. 42m. G.M.T. 

 a bright meteor was seen from Bristol, Stowmarket, 

 Wimborne, and Plumstead, S.E. It had a very long 

 horizontal flight of about three hundred and thirty-five 

 miles at a velocitv of thirty-three miles per second, and 

 passed from over a ooint twenty miles north-east of 

 York to thirtv miles south-west of St. Valery, France. 

 Its height was about seventy-four miles, and its radiant 

 at 156° -1-39°. It is very suggestive that the radiant 

 point of meteors from 'the comet of 1739, as com- 

 puted by Prof. A. S. Herschel, was at 157° + 39° 'or 

 October 22; meteor speed = 39 miles per second. The 



