2l6 



NATURE 



[April 14, 192 1 



means of obtaining news of Spanish scientific work. 

 One original article gives an account of the Medusae 

 found on the coast of Catalonia, and another describes 

 the geology of the country between Tortosa and Cas- 

 tellon. There is also an illustrated article on the 

 National Museum of Natural History at Madrid, 



Among recent publications on mineral oil may be 

 mentioned Bulletin 652, U.S. GeoL Survey, on "The 

 Gushing Oil and Gas Field, Oklahoma," and Bul- 

 letin 656 on "Anticlines in the Bighorn Basin, 

 Wyoming." The Gushing field has been opened up 

 since 1912 with such rapidity and success that con- 

 siderable waste occurred. Its describer, C. H. Beal, 

 believes that the oil and gas have collected from the 

 broad gathering-ground provided by the gentler slope 

 of the anticlinal to the west, the gas arriving first 

 into the crest of the fold, and banking up a following 

 oil-pool west of it. The field in southern Wyoming is 

 in Gretaceous strata, and here again it is pointed out, 

 by D. F. Hewett and C. T. Lupton, that there is 

 most likelihood of oil where upfolds occur near large 

 areas of gently rising beds. The area of supply con- 

 trols the quantity in the anticlines. In the " Summary 

 of Progress of the Geological Survey of Great Britain 

 for 1919" (1920, 2S. 6d.) some details are given 

 of the recent borings iw oil in Derbyshire and Staf- 

 fordshire. The Lower Carboniferous shales, and not 

 the limestone, are regarded as the probable source 

 of such oil as has been found. 



We have received the fifth list (for 19 17) of the 

 earthquakes registered at the observatory of De Bilt, 

 Holland. This station is provided with a pair of 

 Galitzin seismographs, a Wiechert astatic seismo- 

 graph, and a pair of Bosch horizontal pendulums. 

 The catalogue, which is one of the most complete 

 issued, gives for each of the 394 earthquakes recorded 

 the time, period, and amplitude of every phase, with 

 a summary of the times of the principal phases at 

 other observatories and the position of the epicentre 

 when that is known. The munitions explosion in the 

 north of England on October 1, 19 17, was manifested 

 in Holland by the rattling of windows, etc., while 

 that of East London on January 19, 1917, apparently 

 passed unnoticed. 



The Danish Meteorological Institute has published 

 the issue for 1920 of the annual report on the state of 

 the ice in the Arctic seas. The year showed several 

 peculiarities in amount and distribution, although 

 information was lacking from many regions. In the 

 Barents Sea ice was much scarcer than usual, and 

 there was open water as far east as Novaya Zemlya 

 all the summer, while even the Kara Sea offered fewer 

 diflficulties than in normal years. On the west coast 

 of Spitsbergen the condition differed little from the 

 normal, but Storfjord was exceptionally free from ice 

 in late summer. There is little information from the 

 east coast of Greenland, but. more ice than usual 

 passed round Cape Farewell into Davis Strait. This 

 meant that the ice must have been packed close 

 against the east coast, since the shores of Iceland 

 were practically free from ice throughout the year. 

 NO. 2685, VOL. 107] 



On the Newfoundland Banks icebergs were numerous, 

 and drifted somewhat further south than usual during 

 the first half of the year. In Davis Strait and Mel- 

 ville Bay the ice was more abundant than usual during 

 the spring and early summer. 



The index-numbers of vols, xxiii.of the Physics and 

 Electrical Engineering Sections of Science Abstracts 

 complete the volumes for the year 1920. As compared 

 with the volumes for 1919, the Physics Section with 

 its 750 pages shows an increase of about 90 pages, 

 and the Electrical Engineering Section with 633 pages 

 an increase of 150 pages. The number of physics 

 abstracts has increased from 1580 to nearly 1670, and 

 that of the electrical engineering abstracts from 940 to 

 nearly 1120. These changes bring the two volumes 

 back to, pre-war dimensions, although the number of 

 articles abstracted is still considerably below the pre- 

 war number. Unless there is a marked change in 

 the importance of the articles abstracted^ this increase 

 in the average length of an abstract cannot be regarded 

 as altogether satisfactory. Apart from this tendency, 

 the volumes retain their positions as annual records 

 of the progress of physics and electrical engineering, 

 with which no worker who requires accurate and up- 

 to-date information can afford to dispense. 



An interesting paper by Mr. G. Stead was read to 

 the Institution of Electrical Engineers on March 16 in 

 which the effect of electron emission on tTie tempera- 

 ture of the filament and anode of a thermionic valve 

 was investigated. It was found that the temperature at 

 any point on a tungsten filament which was emitting 

 electrons was altered by the passage of the emission 

 current through the filament and by the latent heat of 

 evaporation of the electrons. Direct measurements 

 were made with an optical pyrometer of the tem- 

 perature along the emitting filament. It was found 

 that the distribution of temperature was unsym- 

 metrical, the negative limb being hotter than the posi- 

 tive limb. An account is also given of measurements 

 of the temperature of an anode undergoing electron 

 bombardment. The curve obtained, which shows the 

 relation between the anode temperature and the 

 number of watts dissipated by the anode per sq. cm. 

 of surface, will prove useful to manufacturers. 



On March 17 Sir William Noble read a paper to 

 the Institution of Electrical Engineers on "The Long- 

 distance Telephone System of the United Kingdom." 

 It deals mainly v^ith the improvements that have 

 been made in line-plant design during the last ten 

 years. The recent expansion of long-distance tele- 

 phony has led to a congestion of the pole lines along 

 roads, railways, and canals. Improvements, however, 

 in underground long-distance telephone cables have 

 led to a solution of the difficulty, and practically all 

 the new trunk lines are. In consequence, underground. 

 The three-electrode thermionic amplifier can be used as 

 a telephone repeater, and its general introduction has 

 revolutionised long-distance communication schemes. 

 Amplifiers can also be used to obtain duplexing — that 

 is, both-way working of the line. "Wired wireless" 

 or,' as it is better called, "high-frequency carrier-wave 



