April 15, 1922] 



NATURE 



489 



Research Items. 



An Artifice of Nectar-Sipping Birds. — In a 

 )mmunication sent to us by Mr. P. M. Debbarman 

 )f the Royal Botanic Gardens, Sibpur, Calcutta, he 

 :ords that the flowers of Casianospermum australe 

 re visited by the nectar-sipping bird Mirafra assamica 

 India. The beak of this bird is not sufficiently 

 jng to reach the nectar in the calyx cups, so 

 16 bird appears to have adopted the practice 

 biting off the fleshy petals which obstruct it. 

 le tree is not a native of India but is of Australian 

 igin, and it would be interesting to know whether 

 ly nectar-sipping birds attack the blossoms of this 

 ree in Queensland, where it is native. 



Ice in the Arctic Seas in 192 i. — The annual 

 publication of the Danish Meteorological Institute 

 Tsforholdene i de Arkiishe Have) shows that ice 

 )nditions last year in the Barents and White Seas 

 irere somewhat unusual. The eastern part of the 

 ' irents Sea was free from ice early in May, while in 

 le north the edge of the pack was more northerly 

 lan usual throughout the summer. The White Sea . 

 ms easily accessible and almost free of ice as early 

 April. On the west coast of Spitsbergen, there was 

 )nsiderably less ice than usual during the winter 

 1920-21. The fjords were frozen only for short 

 ;riods and pack-ice did not appear off the coast in 

 ly quantity before May, but throughout the summer 

 lonths there was a belt of loose pack off the south- 

 west coast, which in October increased in width to 

 70 miles. This occurrence was associated 

 ith the prevalence of easterly winds in the Barents 

 in summer. The same winds caused the ice 

 to be packed against the east coast of Greenland in 

 July and August. The distribution of ice in the 

 Greenland Sea was normal except in this respect, 

 which made the east coast of Greenland singularly 

 unapproachable. On the Newfoundland banks ice- 

 bergs were very numerous in May and again in 

 July, when they drifted rather far south. In the 

 Bering Sea, the edge of the pack seems to have been 

 more northerly than usual in spring. In the Beaufort 

 Sea a whaler reached Banks Land in August. 



Seismological Stations of the World. — A 

 valuable catalogue, and the most complete so far 

 issued, of the seismological stations of the world 

 has been compiled by Mr. H. O. Wood under 

 the auspices of the Section of Seismology of the 

 American Geophysical Union (published by the 

 National Research Council of the National Academy 

 of Sciences, Washington, 192 1). The total number 

 of stations is about 315, and for each is given, 

 when known, the position and the nature of the 

 foundation, the names of the director and of the 

 supporting institution, the types of seismographs 

 used and the constants of each, and the method of 

 obtaining correct time. With regard to more than 

 90 of them (including all the Russian stations), how- 

 ever, no recent details have been communicated. 

 Arranging the stations according to countries, we 

 find that Japan heads the list with 55, followed by 

 the British Empire and Italy with 42 each, the United 

 States with 32, and Germany with 21. The instru- 

 ments used are almost as diverse as the countries. 

 The niost popular is the Wiechert inverted pendulum, 

 of which there are 72 in use with masses varying from 

 80 kg. to 17,000 kg. at Gottingen and Tacubaya 

 (Mexico) respectively. Then come the Omori hori- 

 zontal pendulum, extensively used in Japan, the 

 Milne seismograph, chiefly at British stations, and 

 the Vicentini seismographs, employed as a rule in 

 Italy. The costly, but effective, Galitzin seismo- 



graphs are in working order at not less than eight 

 stations. Two points of some interest are the large 

 number of stations founded during and since the war 

 and not in neutral countries only, and the gradual 

 replacement of the older instruments by others of 

 more recent and accurate types. 



The Cement Oilfield, Oklahoma. — A recent 

 addition to our knowledge of the Mid-Continental 

 Oilfield region of North America has been made by 

 Mr. F. Reeves in Bulletin 726-B of the United 

 States Geological Survey, wherein he deals with the 

 geology of the Cement Oilfield, Caddo County, South- 

 west Oklahoma. The area described occurs to the 

 north of one of the main uplift masses (Wichita 

 Mountains) which form such a conspicuous feature 

 of the country bordering northern Texas, and the 

 local tectonics of the field have intimate connection 

 with this larger element of structure. The surface 

 geology is mainly Permian (Red Beds), forming a 

 vast plain surrounding the Wichita Mountains. This 

 formation consists, of shales, sandstone, gypsum and 

 limestone, and, according to the author, has a total 

 thickness of 1500 feet. Beneath it lies the Penn- 

 sylvanian Series, and it is presumed that the oil is 

 obtained from the upper beds in this series, though 

 some difference of opinion is manifest as to where the 

 line of junction should be drawn, the transition from 

 the older to the newer rocks being very gradual. 

 The principal structural feature of the Cement area 

 is the Cement anticline with its complementary 

 synclines, the Cobb on the north and the Cyril on 

 the south. The trend of these folds is approxi- 

 mately N. 70° W., a strike direction characteristic 

 of the Wichita Mountains. The wells are located 

 practically on the crest on the Cement fold, and 

 have an average daily production of about 100 

 barrels ; twenty-six wells have at present been 

 drilled. The oil is of uniform quality with specific 

 gravity ranging from 0-84 to 0-85. The prospects of 

 the field are good, though it is unlikely' that any 

 startling developments will take place in the future, 

 as the productive area is not great and the tendency 

 seems to be for the wells to give low production 

 with slow decline, the rate of decrease averaging 2 

 per cent, per month. Four gas wells have been 

 drilled and the initial production was good, but the 

 rate of decline of these wells was very rapid. The 

 Bulletin itself is quite up to the usual standard of 

 Survey publications in the matter of descriptive 

 text and particularly in the maps and plans accom- 

 panying it. < ^ 



Land and Sea Breezes tx 1111, (.1 lf of Lions. — 

 An article by Prof. M. Moye is given in the 

 Meteorological Magazine for March on land breezes 

 and sea breezes oii the French and Catalonian coasts 

 of the Mediterranean Sea. They are stated to be a 

 distinctive feature of the summer climate in these 

 parts, and are said to be much more marked than on 

 the Channel and Atlantic shores. From a discussion 

 by Prof. E. Fontsere, it is shown that at Barcelona 

 sea breezes begin in March, when they blow on about 

 four days out of ten. In April and May they blow 

 on more than six days out of ten, and from July 15 

 to August 15, sea breezes are recorded on nine days 

 out of ten. In September they are less frequent, and 

 by the end of October they practically disappear. At 

 Montpellier sea breezes are said to be rare before mid- 

 May and after September. The sea breezes generally 

 begin after a short period of calm. During the night 

 and in the early morning land breezes blow gently. 

 The sea breeze begins from the south and south- 



:o. 2737, VOL. 109] 



