45- 



NATURE 



[February 6, 19 19 



l-< ik printing-oul photographic processes, such as 

 printing, Mr, S. S. Richardson in the British 

 Journal "i Photography of January 24 recommends 

 hi new "Pointolite" lamp. This lamp needs so 

 little current that special wiring is not necessary, and 

 it will allow of, say, sis negatives being printed From 

 simultaneously, th< exposure being iboul three- 

 quarters of an hour with negatives ol average density. 

 Mr. Richardson also recommends the iron arc if a 

 current of 5 or 6 amperes is available, using iron 

 instead of the usual carbon poll s. \ lamp so ar- 

 ranged will run sometimes foi hours without atten- 

 tion, as the iron burns awa\ verj slowly. \t .1 

 distance of 50 centimetres thi exposure required is 

 about twenty minutes. With such "point" sources 

 of light an ordinan gla negative may be printed 

 "reversed" for the single transfer carbon process if 

 ordinary care is taken to prevent troublesome reflec- 

 tions and movement of the negative during the 

 exposure. 



A paper on electric welding and three others on 

 oxy-acetyleni welding wen read at the Institution of 

 Mechanical Engineers on January 24. In his paper 

 on electric welding Mr. Thomas T. Heaton says that 

 in his opinion — based upon many years' experience — 

 each known system of welding has its proper sphere, 

 and that probably any given method may be the best 

 in its respectively most suitable application. In the 

 Benardos system of arc welding, direct current is 

 employed at 90 volts and 250 to 500 amperes, accord- 

 ing to the thickness of metal. The arc may be lA in. 

 to 2 in. in length, and the heat may be spread over a 

 fairly large surface, thus avoiding extreme local 

 stresses. The work is positive to a carbon electrode. 

 In the Kjellberg system a metallic electrode is used 

 instead of carbon. The work is negative to the elec- 

 trode, so that the natural tendency is to deposit the 

 metal of the positive electrode on. to the work. The 

 electrode is coated with a fusible silica flux, which 

 prevents oxidation and insulates the electrode. The 

 arc dissipates this flux, leaving no slag. Generally, 

 the electrodes are of 3/16 in. diameter soft iron wire. 

 Mr. Heaton does not find this system to be satisfactory 

 for plates thinner than 025 in. The quasi-arc process, 

 invented by Mr. Arthur Strohmenger, of London, also 

 employs metallic electrodes, and some excellent results 

 are obtained by it. Various coatings may be applied 

 to the electrodes, and may be of such a nature as to 

 supply constituents that are burnt out of the metal 

 in welding. Blue asbestos yarn is especially preferred 

 as a coating in wilding iron or mild steel, as it forms 

 a reducing flux, and it may be smeared with a com- 

 position such as sodium silicate or aluminium silicate, 

 ,1,., to van the fusing temperature of the yarn. 

 Descriptions of some useful testing machines for welds 

 luded in Mr- Heat. m's paper. 



//. K. Lewis and Co., Ltd., have in the 



pies- two hooks by Sir ]. W. Barrett, viz. "A Vision 



ot thi ibli : What the R.A.M.C. Might Become'.' 



and 1 Work of the V.M.C.A. in Egypt," 



illustrated. Tin latter work will contain a prefaci b> 

 (,, n. Sii : H. Vllenby. The Library Press, Lid., 



is bringing Practical Shell Forging and the 



Plastic Defon 1 oi Steel and its Heat Treatment,'.' 

 bj C. <>. Bov Messrs. Armstrong, Whitworth, 



a ' n< j Co., Ltd ct ol the woi I is to show the 



ways in which h) lie plant can be profitabl) em- 

 ployed in peace-tiun lu tion. Messrs. J. M. Denl 

 ,i,i,i Sons, Ltd.. — i x ■ 1 1 "New Town: A Pro- 

 posal in Agricultural, ■ 1. Educational, Civic, 

 and Social Reconstructio '> W. II- Hughes. 

 A NEW weeklx periodic: u tO I" published 

 fat s Bouverie Street, E.< ntitled II ays and 

 Means 1 II ( ekly Ri v'u . 0) Industry, 7 rade, Com- 



NO. -'57 I. VOL. I02] 



mene, and Social Progress. Anion- the editorial 

 features promised in the prospectus issued are Colonial 



development, expert opinion, industry and money* 

 Government finance, education in relation to industry, 

 industrial administration, reconstruction, art in indus- 

 try, science and industry, organisation and system, 

 and welfare. 



OUR ASTRONOMICAL COLUMN. 

 Borrelxy's Comet.- This comet was under observa- 

 tion by Mr. R. L. Waterfield in Cheltenham during 

 January. On January c| it was a faith easv object 

 with 3-in., the magnitude being between 9-0 and 9.5; 

 on Januarj 26 ii was still visible with 3-in., but 



much more difficult. The following is a short exten- 

 sion of the ephemeris (for Greenwich midnight): 



R.A. N. Decl. Logr Log.1 



Februan 6 6 ;t 57 fib 14 0-2210 9-9607 

 10 h 36 17 66 6 0-2281 9-9815 

 14 6 41 48 65 52 0-2345 0-0014 



|S 48 20 65 54 0-2410 0;0203 

 22 6 55 39 65 I I 0-247(1 OO38I 



Reid's Comei (1918a). Circular No. 45 of the 

 Union Observatory, Johannesburg, gives the following 

 positions ot this comet made by Mr. H. E. Wood, 

 and the. orbit which he deduced from them: — 



G.M.T. 1918 R.A. 1918-0 s. Decl. 1918-0 



June 13, 1968 o 1 1 36-52 n 5 55-3 



16, 1986 9 16 47-12 n 58 44 s 



it), 1982 9 17 448 14 40 515 



T = i9i8 June 5-275 G.M.T. 

 <o =194° 7' 18") 

 Sl= 17° 49' 28" [1918-0 

 i = 70 8' 41"; 

 log q =0-04194 



Middle place, obs.-comp. R.A. —11", deck o". The 

 orbit does no! show a close resemblance to any in the 

 catalogues. This was the only comet observed in 

 1918 that did not in long to the Jupiter family. 



Astronomy in thi-: "Times." — We directed attention 

 last week to the important new features in the 

 meteorological reports in the Times, and have now 

 pleasure in referring to another scientific innovation 

 which appeared in the issue for February 1. A map 

 is given, on the zenithal equidistant projection, of the 

 slais ami planets visible in London at 10 p.m. in mid- 

 Februarv, together with the path of the moon and 

 .-in satellite's positions and phases at two-daj intervals. 

 There is accompanying letterpress by an astronomical 

 correspondent, describing the leading points of interest 

 in the constellations and directing attention to the 

 approaching conjuricion (in 1021) of Jupiter and 

 Saturn, which are now such conspicuous objects. II. as 

 we understand, this is the in ^t oi .< series of monthly 

 maps and articles, they are likely to lead to a con- 

 iderable awakening of interest in astronomy on the 

 part of ih, g< neral public. 



Tm- Energy 01 Magnetk Storms. Dr. S. Chap- 

 man contributes a paper on this subject to_ the 

 Monthlj Notices for November last. He con'si 



thai the sun is the source of energy, and that it is 

 transmitted b\ streams of electric corpuscles. These 

 ionise ,-md charge the absorbing layei in the atmo- 

 sphere. The accumulation oi charg ues until 



the electrostatic repulsion overcomes gravity, when the 



electrified gas is impelled upwards, the atmosphen 



thus losine both its charge and part of its suhsi 



1 . s formi rh 1 onsidei ed that to make the sun the 

 souro of energy would involve an inconceivable 

 ,111, mm of output From the sun, hut under the new 

 this is not the case. 



