624 



NATURE 



[July 15, 1920 



the ^staple diet of the fur-seal. This aspect of the 

 problem adds to its complexity, since it affects con- 

 flicting interests. At the same time it emphasises 

 the need for immediate action, not for academic dis- 

 cussion. 



The many friends of the veteran geologist, Mr. 

 Henry Keeping, who was born near Milton, on the 

 Hampshire coast, in 1827, will welcome his simple 

 <ind unaffected "Reminiscences," published as a 

 pamphlet by F. W. Talbot, Sussex Street, Cambridge 

 (price IS. 6d. post free). A characteristic portrait 

 appears on the cover. Anecdotes of Sedgwick and 

 of the early days of collecting in Devonshire and the 

 Isle of Wight form pleasant reading. The story of 

 the plump farmer in the Fenland who checked a 

 disaster by sitting in the gap of a broken dyke is 

 told with humorous appi'eciation. 



Prof. Pierre Termier, in a paper on " Les Oceans 

 h. travers les figes " {Revue Scientifique, May 8, 1920), 

 emphasises the differences in structure of the Atlantic 

 and Pacific Oceans, and regards the deep-water ring 

 around the central area of the latter as a per- 

 sistent feature of the crust, liable to disturbances, but 

 not to elevation as dry land. The Indian Ocean, 

 on the other hand, is post-Jurassic and the Atlantic is 

 post-Miocene. The narrowing of the continents south- 

 wards is not a primary feature of a tetrahedral earth, 

 but results from the widening of these comparatively 

 modern areas of subsidence as they approach the 

 south. 



The Geographical Review (New York) for March, 

 1920, contains two articles of especial interest to 

 British readers. The first is by Lieut. Leo Walmsley 

 on "The Recent Trans-African Flight," with several 

 photographic illustrations. The writer's wide know- 

 ledge of Eastern Africa and his success as a scientific 

 observer even when fighting from his aeroplane fully 

 justify his remark that " Africa, as seen from the 

 air, is one of the most wonderful of all countries. 

 ... A civilised country seen from the air is simply 

 a gigantic mosaic ... the airscape of Central Africa 

 is as untamed and irregular as that of the 

 moon." The second article is by Mr. C. R. Dryer 

 on " Mackinder's ' World Island ' and its American 

 ' Satellite. ' " The author cleverly shows, on Moll- 

 weide's projection, the American continents as a 

 "world ring" round about the "world island," and 

 pictures the people of that world ring, which has no 

 barbarous heartland, as ready to come to the aid of 

 the coastal races that stand for civilisation in the 

 world island. 



Stonyhurst College Observatory has recently issued 

 the results of meteorological and magnetical observa- 

 tions for 19 19 with a report and notes by the director, 

 the Rev. A. L. Cortie, S.J. The results with the 

 report occupy 55 pages, and details of the observa- 

 tions are given with great precision for the several 

 months and for the year. The observatory has long 

 since been associated with the Meteorological Office, 

 and the Monthly Weather Report publishes many of 

 the results. The monthly mean temperature is 

 NO. 2646, VOL. 105] 



obtained in two ways, from the mean of the highest 

 and lowest daily readings and from the mean of the 

 readings at 9 a.m. and 9 p.m., both means being 

 corrected by Glaisher's tables. The thermometers are 

 mounted 7 ft. above the ground in a Stevenson screen ; 

 why in this case should not the height above ground 

 be 4 ft., the normal height for uniformity? Taken 

 as a whole, 1919 was drier and colder than the normal, 

 and every individual month was cold with the excep- 

 tion of May and December. Bright sunshine for the 

 year was 25 hours less than the normal. Rainfall was 

 ntearly 6 in. deficient, although the rainy days were 

 only two fewer than usual. October was relatively 

 the driest month, rainfall being only about 50 per Cent, 

 of the average. Magnetic observations and disturbances 

 are popularly explained, and afford considerable in- 

 formation for obtaining uniformity of results. Sun-spot 

 activity, which had steadily declined since August, 

 1917, and throughout 1918, revived in 1919. The 

 seismograph, which for a time had been thrown out 

 of action, is said to be now working satisfactorily. 



Mr. J. I. Graham, research chemist at the Bentley 

 Collieries, Doncaster, has devised a verv convenient 

 and portable apparatus for the estimation of small 

 quantities of carbon, monoxide in the air of mines. It 

 consists of a vessel containing a known volume of 

 the sample, which can be introduced by running water 

 out of the vessel. By operating a three-way tap and 

 blowing water into the vessel the sample may be 

 passed into iodine pentoxide contained in a U-tube 

 heated to 9o°-i5o° C. In examining air in the mine 

 the temperature is maintained by hot oil contained 

 in a thermos flask which keeps the U-tube within 

 these limits for several hours. The iodine liberated 

 from the pentoxide is thus sublimed and driven into 

 a tube containing a solution of potassium iodide in 

 which the free iodine can be titrated and estimated 

 in the usual way. The inventor claims that an 

 analysis can be completed in about five minutes with 

 an accuracy of 0005 per cent, using 100 c.c. of air, 

 or of 00005 per cent, with i litre. It is of special 

 value for estimating small quantities of carbon 

 monoxide in mine-air, since 0-2 per cent, is highly 

 dangerous, and even 0-02 per cent, produces after a 

 time unpleasant effects. As the quality of compressed 

 oxygen supplied in cylinders is important in life- 

 saving operations in mines, Mr. Graham has 

 introduced a simple piece of apparatus for deter- 

 mining the amount of oxygen by absorbing a known 

 volume in alkaline pyrogallol. Both ' pieces of 

 apparatus can be purchased from Messrs. Reynolds 

 and Branson, Ltd., Leeds. 



In order to obviate the use of the high voltages 

 required in wireless telegraphy when a triode tube is 

 operated from a direct. current supply by means of a 

 mechanical "chopper" which periodically breaks the 

 supply circuit, Mr. L. M. Hull, of the Bureau of 

 Standards at Washington, has used with great success 

 an alternating supply from a 2-kw. machine giving 

 5C0 cycles per second at 150 volts, and a short account 

 of his method and results is given in the Journal of 

 the Washington Academy of Sciences for June 4. 

 The sending key is in the alternator circuit, and the 



