September 16, 1922] 



NA TURE 



597 



were deposited at or below sea-level, and their occur- 

 rence above this has been held as evidence of elevation. 

 We have here an instance which indicates that this 

 is not necessarily the case, for such a lamina would 

 be produced if a new outpouring of lava were to cover 

 up the place mentioned." 



Cainozoic Fishes of California. — In a paper 

 on the fossil fishes of the diatom beds of Lompoc, 

 California (Leland Stanford Junior University 

 Publications, 1920), David Starr Jordan and James 

 Zaccheus Gilbert direct attention to beds of Miocene 

 age, probably formed in a quiet, shallow, marine bay ; 

 they are rich in large diatoms and " heavy " radio- 

 laria. At one special horizon an extinct herring, 

 Xyne grex, is represented by an immense number of 

 individuals, all adult, all about six inches long, and 

 unmixed with any other fish. They appear to have 

 entered the bav with the view of spawning, and to 

 have been killed suddenly " with no evidence of agony 

 or distortion." In a subsequent paper, on " The Fish 

 Fauna of the California Tertiary" (Stanford Univ. 

 Publications, Biol. Sci., vol. i. No. 4, 192 1), Dr. Jordan 

 gives very interesting restorations of a number of fossil 

 fish in a series of captivating plates, preceded by 

 photographs of their skeletons. He refers again to 

 the remarkable shoal of herring, which provides 8 

 or 10 specimens to the square foot over an area of 

 four square miles. It is estimated that 1200 million 

 individuals perished on this one occasion. Though 

 it is said that Dr. Mann has offered an explanation, 

 we are unable to trace it in these memoirs. 



Carbon-Black in the United States. — Recent 

 articles in Nature have directed attention to 

 the various products obtainable from natural gas, 

 among which petroleum, allied light oils, and helium 

 figure prominently. An important industry also 

 exists for the purpose of manufacturing carbon-black 

 from this source, this product forming the basis of 

 such commodities as printers' ink, paints, varnishes, 

 polishes, cement colours, etc. It is also considerably 

 used in the rubber industry for increasing the 

 resiliency and toughness of rubber tyres. The 

 processes of extraction of carbon-black from natural 

 gas are confined principally to the United States, 

 Louisiana being the leading state in this respect, the 

 other producing states being West Virginia, Ken- 

 tucky, Oklahoma, Pennsylvania, Montana, and 

 Wyoming. The industry thrives best where there is 

 an abundant supply of natural gas available in fields 

 sufficiently isolated as to inhibit the use of the gas 

 for domestic purposes. The yield of carbon-black 

 per thousand cubic feet of gas ranges from 0-2 lbs. 

 to 3-5 lbs., and in 1921 more than 31 million pounds 

 were produced by Louisiana alone, the average yield 

 being 0-97 lbs. per m. cub. feet. The total production 

 for the United States for that year amounted to 

 59,766,315 lbs., valued at 5J- million dollars (E. G. 

 Sievers, Min. Resources Unit. States, 1921, pt. ii. p. 

 33). Recent legislation in some states, in particular 

 Louisiana, has tended to check the progress of this 

 industry, since the rapid advancement of natural 

 gas gasoline manufacture (a far more valuable 

 product) has resulted in the conservation of natural 

 gas for that purpose. Operators are therefore 

 compelled to extract the gasoline from the gas before 

 the latter is burned in the carbon-black plants. In 

 some cases this has served to eliminate the industry 

 altogether, but by adapting and by using the gasoline 

 and carbon-black plants in conjunction, such calamity 

 can be, and is being, fortunately avoided. 



The Course of Photographic Development. — 

 Forty-five years ago, Abney (Phil. Mag., 1877) coated 

 exposed plates with a second sensitive film before 



development. After development he stripped off the 

 second film and found that a part of the image was 

 in it — that is, the development had spread from the 

 exposed to the unexposed sensitive material. On 

 the contrary, common experience with gelatine- 

 plates shows conclusively that when the exposure is 

 insufficient it is impossible to develop an image of 

 the maximum density that the plate can yield. If 

 development spreads at all from exposed to unexposed 

 particles, the spreading effect must be very limited. 

 Recently, this matter has been investigated in the 

 modern, microscopical manner, by tracing the changes 

 in the particles themselves. Prof. The. Svedberg has 

 shown that developability is not conferred by develop- 

 able grains upon contiguous grains, and that the 

 percentage of grains developed is not increased when 

 the grains are " closely packed together." In the 

 September number of the Journal of the Roval 

 Photographic Society, Messrs. A. P. H. Tri\ . lli, 

 F. L. Righter, and S. E. Sheppard, of the Research 

 Laboratory of the Eastman Kodak Company, give 

 details of their experiments, which show that where 

 a group of two or more grains forms a " clump," 

 this clump develops as a unit, and if only one of the 

 constituent grains has been made developable, the 

 whole group is completely developable. Thev used 

 Svedberg's methods. They consider that Svedberg 's 

 results are conclusive evidence that developability 

 in his case was not transferred from one grain to 

 another, and ascribe their apparently contradictory 

 results to the character of the emulsion. Svedberg 

 used a special emulsion with mostly spherical grains 

 of nearly uniform size, while the authors' emulsion 

 had a wide range of grain sizes and contained main- 

 large polyhedral tablets. Obviously this matter is of 

 fundamental importance from a theoretical point of 



Upper Air Research. — Part I. of an aerological 

 survey of the United States, the results of observations 

 by means of kites, by Mr. W. R. Gregg, is published 

 as Supplement No. 20, U.S. Monthly Weather Review. 

 An abstract by the author is also given in the Monthly 

 Weather Review for May last. The object of the dis- 

 cussion is to furnish results so much needed at the 

 present time in connexion with aviation and ordnance. 

 Much detailed information can be obtained from the 

 numerous tables and diagrams as to the character- 

 istics of the free air over the United States east of the 

 Rocky Mountains. Kite observations are made at 

 six stations established by the Weather Bureau 

 during the period 191 5 to 19 18, and there are data 

 from other sources. Various meteorological results 

 for the upper air are given for the several months, 

 the season, and the year. The values at Blue Hill, 

 Mass., and Mount Weather, Va., each based on a long 

 series of observations with kites, are included m the 

 discussion. Free-air results will augment the general 

 knowledge of atmospheric circulation, and of the 

 movements of cvclones and anticyclones. It is 

 rightly claimed that they will give information of 

 value in connexion with the laying out of a per- 

 manent flying course or " air-way." Near the surface 

 the turning of the winds is generally to the right, and 

 the deviation is greater in winter than in summer ; 

 moreover, it is greater at northern than at southern 

 stations. The average wind velocity at lower levels 

 increases most above surface south-easterly to south- 

 westerly winds, but at greater heights the largest 

 increases are found above surface south-westerly to 

 north-westerly winds. The velocities are least in all 

 seasons and at all heights above surface north-easter! y 

 to east-south-easterly winds. A review of pilot- 

 balloon observations is foreshadowed at a future 

 date. 



NO. 2759, VOL. I io] 



