296 



NATURE 



[November ii, 191 5 



it is pointed out that already 45 per cent, of the shares 

 are held by Alsatians or Frenchmen, so that such a 

 scheme is scarcely legitimate. Under the German 

 rdgime the part reserved to the Alsatian mines by the 

 Kalisyndikat of Stassfurt represented only 10 per cent, 

 of the total sales, although a policy of free competition 

 would have justified a far greater output. It is, how- 

 ever, probable that after the war arrangements will 

 be made allotting to the Alsatian mines at least 25 per 

 cent, of the total world's supply. The development 

 of the Catalonian mines may modify this figure, but 

 the development in this field promises to be slow. 



We have received a copy of the first issue of the 

 Journal of the Association of Official Agricultural 

 Chemists (Baltimore, U.S.A. : Williams and Wilkins 

 Co.), of which the Syndics of the Cambridge Univer- 

 sity Press have undertaken the agency in the British 

 Empire. The journal will be the official medium for 

 the presentation of data and analyses in the domain 

 of agricultural chemistry, and will include the pro- 

 ceedings of the association, reports of scientific re- 

 search, and complete statements of the official methods. 

 Until recently the work of the association has been 

 included in special bulletins published by the Bureau 

 of Chemistry of the U.S. Department for Agriculture; 

 the publication in journal form will make this work 

 available to a large public. The purpose of the associa- 

 tion is to secure uniformity and accuracy in the methods, 

 results, modes of statement of analysis of fertilisers, 

 soils, foods, dairy products, medicinal plants, drugs, 

 and other matters connected with agricultural industry. 

 The journal, therefore, is of importance to the chemist, 

 the agriculturist, and the manufacturer. It will be 

 published quarterly, and each volume will consist of 

 about 600 pages. The subscription price is 23s., post 

 free. Subscriptions may be sent to Mr. C. F. Clay, 

 Cambridge University Press. 



Every engineer who, since the war began, has taken 

 up the manufacture of war material has found himself 

 hampered, and his output delayed, by the Wool- 

 wich regulations for inspection and gauging. 

 The leading article in the Engineer for October 

 29 gives an interesting example of regulations which 

 might be relaxed in the present circumstances. In the 

 manufacture of steel bars for shells, the Government 

 brand is put upon the material at every stage of its 

 progress. The cast ingot is stamped, then the billet, 

 and then the bar rolled from it. From the bar a dozen 

 or more separate pieces, each to make a single shell, 

 have to be cut. The brand is stamped upon the side 

 of each piece before it is cut off. Rough turning 

 removes it, and it has to be renewed on the base, then 

 the base is cut away, and the brand has to be put on 

 the side. In peace time this was splendid — the identity 

 of every shell was preserved. At present there is no 

 reason for keeping this close watch on every piece, and 

 the final test stultifies the whole. Oijly one shell is 

 drawn from a mixed batch of five hundred, and tested by 

 firing from a gun. If it fails the whole mixed batch 

 may be condemned. There are several other cases 

 which might be quoted in which system appears to 

 have run away with intelligence. 

 NO. 2402, VOL. 96] 



Messrs. T. C. and E. C. Jack (London and Edin- 

 burgh) have in preparation for their "Through the 

 Eye" series: — "The Evolution of the Plant," by Dr. 

 H. F. Wernham; "Greek Civilization," by Prof. 

 J. S. Phillimore; "Bird Life," by W. P. Pycraft; 

 "The Evolution of the Bird," by W. P. Pycraft; 

 " Roman Civilization," by A. F. Giles. 



OUR ASTRONOMICAL COLUMN. 



Variability of a Orionis. — In the current number 

 of the Observatory Mr. F. W. Backhouse directs atten- 

 tion to the abnormally diminished brightness of this 

 star. On October 14 it appears to have been 05 mag- 

 nitude — one magnitude fainter than usual. 



The Solar Constant. — Criticism of the extremely 

 accordant determinations of the solar radiation made 

 under the auspices of the Smithsonian Astrophysical 

 Observatory has been based almost entirely on the 

 amount of the correction for the elifect of the terrestrial 

 atmosphere. Prof. Very ipaintains that the Smith- 

 sonian observers underestimate this efifect, consequently 

 obtaining a value much too low. Although the Lang- 

 ley method has already been applied under a diversity 

 of conditions — height above sea-level, atmospheric 

 transparency, temperature, etc. — yielding satisfactorily 

 harmonious results, yet unceasing efforts have been 

 made to apply more and more severe tests by carrying 

 out the measures under the least possible superincum- 

 bent air-mass. The most effective way in which this 

 can be accomplished is by raising self-recording in- 

 struments to the greatest possible height in the atmo- 

 sphere by means of free sounding balloons. An 

 account of the most recent experiments of this kind is 

 presented by Messrs. Abbott, Fowle, and Aldrich in a 

 memoir (Smithsonian Misc. Coll., vol. Ixv., No. 4, 

 1915), which forms an important contribution to the 

 subject. Space only permits a hint at the ingenious 

 instrumental devices embodied in the apparatus, the 

 searching laboratory tests, and the manifold correc- 

 tions involved in the reductions. The most successful 

 day ascent was made on July 11, 1914, from Omaha. 

 At a mean altitude of 22,000 metres (nearly fourteen 

 miles) the three best records gave 176 Calories per 

 sq. cm. f>er minute. Corrected to mean solar distance, 

 etc., this becomes 1-84 Calories. The barometric 

 record indicated a pressure of about 3 cm. of mercury 

 {i.e. about 1/25 normal atmospheric pressure. Other 

 pyrheliometric measures have been made at heights 

 corresponding to pressures of 30 cm. (manned balloon, 

 Dr. Peppier), 44 cm. (Mt. Whitney), and 62 cm. (Mt. 

 Wilson). These records, with the maximum value 

 observed by Dr. Kimball at Washington, when plotted 

 lie quite close to a straight line. It is concluded that 

 the Smithsonian value (1-93 Calories) for the constant 

 of solar radiation outside the atmosphere is amply 

 confirmed. 



Proper Motions of Stars in the Region of 

 N.G.C. 6705. — Recently M. Comas Sola announced 

 the discovery of a number of large proper motions in 

 the region of this cluster (Messier 11) by stereoscopic 

 examination of photographs. In view of the consider- 

 able interest recently aroused in this and allied 

 methods of rapidly determining proper motions (see 

 various notes in this column, also in the current num- 

 ber of the Observatory), it is important to note that 

 Prof. E. E. Barnard {Comptes rendus, vol. clxi., 

 p. 411) has examined the region of this cluster in the 

 stereocomparator. Although the pair of plates were 

 separated by an interval of twentj'-two j-ears (approxi . 



