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NATURE 



[January 22, 1920 



average worker. Owing to the workers' insufficient 

 knowledge of the economics ruling industry, he be- 

 lieves that the extra profit thereby derived passes to 

 the employer without relative advantage to the worker, 

 and that the efficiency of employees penalises others by 

 unemployment ; hence scientific improvements must 

 be introduced with foresight and tact. 



Among forthcoming books we notice the following : 

 " Wireless Telegraphy, with Special Reference to the 

 Quenched-spark System," B. Leggett ; ".Aeronautical 

 Engineers," Major A. Graham Clark; "Theory and 

 Practice of Aeroplane Design," S. T. G. Andrews and 

 S. F. Benson; "Physical Chemistry of the Metals," 

 R. Schenk, translated by R. S. Dean; "Manufacture 

 and Uses of .Mloy Steels," H. D. Hibbard ; and 

 "Mathematics for Engineers," W. N. Rose, vol. ii. 

 (Chapman and Hall, Ltd.) ; " The Principles of 

 Anatomy as Seen in the Hand," Prof. F. Wood-Jones, 

 illustrated; "A Text-book of Organic Chemistry," 

 E. de Barry Barnett, illustrated; and "Laboratory 

 Manual of Elementary Colloid Chemistry," E. 

 Hatschek, illustrated (/. and A. Churchill); "Coal, 

 Economy : For Steam Users, Engineers, Enginemen, 

 Boiler Firemen, etc.," W. H. Casmey, and "The 

 Mineralogy of the Rarer Metals," Cahen and Wootton, 

 second edition {C. Griffin and Co., Ltd.). 



The new list of announcements of Mr. John 

 Murray contains many books of scientific interest, 

 e.g. "Science and Life: Aberdeen .Addresses," 

 Prof. F. Soddy ; "Springtime, and Other Essays," 

 Sir Francis Darwin, illustrated (this week) ; 

 "Splendours of the Sky," Isabel M. Lewis, 

 illustrated; "Conifers and their Characteristics," 

 C. Coltman-Rogers, illustrated; "Life of Sir 

 William White, K.C.B., F.R.S.," F. Manning, 

 illustrated; "New Light on Ser Marco Polo," Prof. 

 H. Cordier (a supplement to Sir Henry Yule's "The 

 Book of Ser Marco Polo"); "The Shibboleths of 

 Tuberculosis," Dr. M. Paterson; "Wild Life in 

 Canada," Capt. A. Buchanan, illustrated; "The 

 Heron of Castle Creek, and Other Sketches of Bird 

 Life," A. W. Rees, with a memoir of the author by 

 J. K. Hudson, illustrated ; volumes dealing respec- 

 tively with Hides and Skins, Rice, and Oil Seed (in 

 the Imperial Institute Reports on Indian Raw 

 Materials), and "Tungsten Ores," R. H. Rastall and 

 W. H. Wilcockson (in the Imperial Institute Mono- 

 graphs on Mineral Resources) ; also new editions of 

 "The Interpretation of Radium and the Structure of 

 the Atom," Prof. F. Soddy, illustrated; "Micro- 

 scopy : The Construction, Theory, and Use of the 

 Microscope," E. J. Spitta, illustrated; "Hydro- 

 graphical Surveying," the late Rear-Admiral Sir 

 W. J. L. Wharton, revised, etc., by .Admiral Sir 

 Mostyn Field; "The Soil," Sir A. D. Hall; and 

 "The Small Farm and its Management," J. Long. 



OUR ASTRONOMICAL COLUMN. 



Large Fireball on January 16. — In the evening 

 twilight of January i6, at 4h. 50m., a fireball was 

 observed from London and other places in the Eastern 

 Counties. It gave a brilliant flash and left a luminous 

 trail which assumed curious forms during fully 

 55 minutes. The observations already received of this 

 NO. 2621, VOL. 104] 



object are not sufficiently exact or numerous to allow 

 the real path to be trustworthily determined, but the 

 meteor probably had a radiant in Cygnus at about 

 290° + 53°, and was situated over Lincolnshire. We 

 hope to give more details next week. 



In recent years January has proved itself a month 

 in which fireballs are notably abundant. In 1895, °" 

 January 16, three large fireballs were observed, and 

 the period from January 12 to 17 seems to have been 

 unusually productive of these brilliant objects. 



Prof. W. H. Pickering's Lunar Studies.— Prof. 

 W. H. Pickering has for many years made careful 

 studies of various regions of the moon during the 

 whole period of their illumination by the sun. He has 

 traced several cases of notable changes of relative 

 illumination of adjacent regions, some growing 

 brighter, others darkening, as the sun rises higher. 

 Popular Astronomy for November contains a number 

 of drawings and photographs of the crater Eratos- 

 thenes. The author suggests that the white regions 

 are snow, and the dark regions some low form of 

 vegetation. He imagines that a limited amount of 

 water may remain in certain regions, being held in 

 the soil by capillary attraction. It seems, however, 

 that the phenomena might be otherwise explained bv 

 neighbouring regions being formed of different kinds 

 of rock, or even by their being of different degrees of 

 smoothness. Observations of occultations made on 

 the dark limb show with certainty that no refraction 

 occurs exceeding i"; those made on the bright limb 

 are less precise, but even there the greatest admissible 

 refraction is some 4". Comparing this with the 68' 

 of a tangential ray in our atmosphere, we see how 

 exceedingly rare any lunar atmosphere must be. The 

 suggestion of vegetation is perhaps not absolutely im- 

 possible, but presents grave difficulties. 



With regard to the suggestion made in a 

 publication of the Smithsonian Institution, Washing- 

 ton, D.C., of a rocket to reach the moon, 

 irresistibly recalling the well-known romance of Jules 

 Verne, it seems clear that the propulsive effect of the 

 escaping gases must be trifling beyond the atmo- 

 sphere. A velocity of seven miles per second would 

 therefore be required at the limits of the atmosphere, 

 and considerablv more evidence is needed before this 

 can be admitted as attainable. 



The Solar Eclipse of May 29, 1919. — ^The January 

 number of Conquest contains an article by Mr. C. R. 

 Davidson, one of the observers of the eclipse at 

 Sobral, Brazil. It is illustrated by many views of the 

 locality, eclipse camp, and instruments, and gives a 

 clear statement of the problem which the expedition 

 was sent to solve, and of the successful result. A 

 deflection of light amounting to 1-98" at the sun's limb 

 was indicated bv the measures, which is close to the 

 value 1-75" predicted by Einstein. Photography of the 

 corona and prominences was not part of the aims of 

 the expedition ; indeed, the author points out that if the 

 observers could have dispensed with these they would 

 gladly have done so. since they veiled some stars 

 near the sun that would have been very useful. How- 

 ever, a good record of the corona was obtained. Its 

 shape is a blend between maximum and minimum 

 types ; it would conform more closely to the latter, 

 save for a large streamer at the South Pole. Mr. 

 Davidson and Mr. Woodman directed attention, at 

 the meeting of the R..A.S. on January 9, to the 

 advisability of repeating the observations, with still 

 greater reflnement, at the eclipse of September, 1922. 

 They exhibited a model of a simple form of equatorial 

 mounting, suitable for low latitudes, which would 

 obviate the necessity for employing coelostats. These 

 are admirably adapted for physical researches, but 

 have some defects in a case where extreme precision 

 of position is required. 



