12 



NATURE 



[September 4, 1919 



in France," Sir VVilmot Herringham ; "Tiie Struggle 

 in the Air, 1914-18," Major C. C. Turner; "Memories 

 of the Months," Sir Herbert Maxwell, Bart., sixth 

 series; "Gardens: Their Form and Design," Vis- 

 countess Wolseley ; and " Modern Roads," H. P. 

 Boulnois. Messrs. Thomas Murby and Co. an- 

 nounce : — "An Introduction to Palaeontology," Dr. 

 A. Morley Davies; " Petrographic Methods and Cal- 

 culations," Dr. A. Holmes ; and " A Nomenclature 

 of Petrology," Dr. A. Holmes. Messrs. Scott, Green- 

 wood, and Son have ready for publication the second 

 English edition of "Chemical Reagents: Their Uses, 

 Methods of Testing for Purity, and Commercial 

 Varieties," Dr. C. Krauch ; a new edition, by A. B. 

 Searle, of the translation of E. Bourry's "A Treatise 

 on Ceramic Industries " ; and a new edition of 

 "Modern Brickmaking," A. B. Searle. 



All communications for the Imperial Mineral 

 Resources Bureau should in future be sent to 2 Queen 

 Anne's Gate Buildings, Westminster, S.W. i, to 

 which address the Bureau has recently removed. 



OUR ASTRONOMICAL COLUMN. 



Metcalf's Comet. — The following orbit of the 

 comet discovered by Mr. Metcalf on August 21 is by 

 Miss Vinter Hansen and Mr. Fischer-Petersen from 

 observations on August 21, 22, 25 : — 



T = i9i9 0ct. 16-1984 G.M.T. 

 CO =128° 33-32'l 

 0^ = 311° 22 93' M9i9'o 

 ! = 19" 58-o3'j 

 log g =9'6828o 

 Error of middle place (observed minus computed), 

 + 0-39' -f 0-09'. 

 1 Ephemeris for Greenwich Midnight. 



K.A. N. Decl. hog r Log A 



h. m. R. o 



Sept. s ... 19 13 33 74 S^-z 0-0147 9-3095 



7 ... 16 25 41 76 26-4 9-9997 9-3174 



9 ... 14 19 50 71 48-1 99842 9-3375 



II ... 13 19 10 65 92 9-9681 9-3666 



13 ... 12 47 47 58 37-0 99515 9-4016 



The magnitude remains nearly constant at 6J, so 

 that it is on the verge of naked-eye visibility. 



Prof. Leuschner telegraphs that he identifies the 

 comet with comet 1847 V (Brorsen), which w-as ex- 

 pected about this time. If this is confirmed, it will be 

 the fourth member of the Neptune group to be ob- 

 served at a second return, the others being Olbcrs's, 

 Pons-Brooks's, and Westphal's. Halley's comet is not 

 reckoned. 



The Recent Shower of Perseids.-— The return of 

 these meteors was fairly well observed this year, 

 though the full moon occurring on August 11 greatly 

 moderated the visible aspect of the display. The 

 weather was very favourable, and a considerable 

 number of meteors were recorded by Mrs. F. Wilson 

 at Totteridge, Mr. S. B. Maltey at Ilfracombe, Mr. 

 A King at Scunthorpe, in Lincolnshire, and Mr. 

 Denning at Bristol. The radiant point appeared 

 rather more diffuse or scattered than usual, but it 

 exhibited the usual E.N.E. movement amongst the 

 stars when observed on successive nights. A com- 

 panion shower between a and /3 Persei was stnkmgly 

 evident this year, and it furnished some fine meteors 

 radiating from the point 48° + 44°. Other contem- 

 norarv showers were remarked from 336 - 10 , 

 3io° + 8o°, 3i3° + 48°. 303°-9°. and .303° + 24°; and 

 between August 22-29 many small, slowish meteors 

 were traced from oositions at 332°-!- 57 and 348 +bi . 

 The most brilliant Perseid seen flashed out on 



NO. 2601, VOL. 104] 



August 12 at loh. 32m. G.M.T., and it was recorded 

 at Totteridge, Bristol, and several other places. Its 

 height was from 76 to 51 miles, and it passed from 

 a point above 10 miles W.N.W. from Worcester to 

 10- miles E. of Tredegar in South Wales. 



INTERNATIONAL STANDARDISATION.^ 



jV/r GUILL.\UME, the distinguished director of 

 ■'■'•*-• the Bureau International, is to be congratu- 

 lated on the issue of this important volume. 



And yet it is a sad record ; the greater part is 

 occupied with the proces-verbaux of the fifth Inter- 

 national Conference of Weights and Measures held 

 at Paris in 1913, and attended by representatives of 

 all the principal countries of the world, many of 

 whom will never meet again. Much of the rest is 

 the last work of Pierre Chappuis, whose death is 

 recorded in a note to- one of the papers by M. (iuil- 

 launie, and to whose labours are due the determina- 

 tions of so many important constants. 



The proces-verbaux of the conference demand our 

 first attention, for the meeting was, in many respects, 

 important, and new ground was broken in various 

 directions. The decisions reached by the delegates 

 remain unfulfilled, and it will no doubt be the busi- 

 ness of the sixth conference — which it is general!}- 

 understood is to meet shortly — to consider the steps 

 that should now be taken to give effect to them or 

 to modify them as may seem best ; for on some of 

 the matters discussed considerable difference of 

 opinion may well arise. 



The fundamental business of the conference con- 

 cerns weights and measures, the determination of 

 standards of mass and length, the kilogram and the 

 metre. The accurate calibration of these at once 

 involves the measurement of temperature, and 

 accordingly much of the work of the Bureau has 

 dealt with scales of temperature; the scale of the, 

 constant-volume hydrogen thermometer was chosen 

 as standard, and all temperatures referred to it. 

 For the range 0° to 100°, or, indeed, for one rather 

 outside these limits, this sufficed, but accurate deter- 

 minations of temperature are now required down to 

 the temperature of liquid air and up to perhaps 

 2500° C. Tlie hydrogen thermometer is useless for 

 such a range, and some steps ■ were necessary to 

 secure international agreement throughout the scale. 

 There was no doubt that the absolute thermodynamic 

 scale was the standard to aim at; on the other hand, 

 there was no certainty as to the methods to be taken 

 to realise that scale over the greater portion _ of the 

 range. And so the conference, after emphasising the 

 importance of researches which had for their object 

 the perfecting of our knowledge of thermometric 

 scales, expressed itself as (i) ready to substitute for 

 the international service of weights and measures the 

 Absolute scale in place of the " normal "—I'.e. 

 hvdrogen^scale so soon as the relationship between 

 these scales had, thanks to the researches^ contem- 

 plated, been determined with sufficient certainty, and 

 (2) apjDroving the determination of a certain number 

 of standard temperatures as fixed points of the scale, 

 to be suitably chosen and agreed upon as soon as 



possible. „ , . , ^ 1 



With the view of givmg effect to this last resolu- 

 tion the conference invited the International _ Com- 

 mittee on Weights and Measures to arrange with the 

 directors of the national laboratories which had been 

 dealing with the measurement of temperature to meet 

 at the Bureau to select the standard temperatures and 

 to take steps to secure their general adoption. In 



1 "Travaux et Mimolre. du Bur«i. I...ern.-,.ionr,l dcs Poids et Mesures." 

 Tome xvi. (Paris : Gauthier-Vill.-irs et Cie, 1917) 



