August i i, 1923] 



NA TURE 



2 19 



Ministry of Public Works, Egypt. Daily observa- 

 tions are given for several elements at the principal 

 stations, comprised by Helwan Observatory, which 

 is the first-order station for Egypt, as well as Alex- 

 andria, Giza, and Khartoum. Monthly summaries 

 are given for many other stations, and monthly rain- 

 fall results are added for several places. Weather 

 conditions were generally unsettled from January to 

 April and from October to December, but more 

 settled weather was experienced from May to Sep- 

 tember. The temperature was much above the 

 normal in the autumn months and about normal for 

 the rest of the year, while atmospheric pressure was 

 generally above the normal. Heavy rain of the 

 thunderstorm type over Middle Egypt was a feature 

 of the year. The Sudan rains were in considerable 

 deficit. At Helwan, July was the hottest month of 

 the year and the diurnal change of temperature was 

 greatest; the mean temperature was 28-8° C, and 

 at 5 A.M. the deficit of temperature was 6-7° C, 

 while at 3 p.m. there was an excess of 6-7° C. The 

 lowest mean temperature was 12-6° C. in January. 

 The total rainfall for the year at Helwan was 36-7 mm. 

 (1-45 in.), and no rain fell from June to September. 

 Observations were commenced at Jerusalem in April 

 1918 ; the hottest month was July with a mean 

 22-8° C, while in December the mean was io-o° C. 

 No rain fell in June, July, and August ; in December 

 the total rain was 105-1 mm. (4* 14 in.). 



Pectin in Cotton. — Messrs. P. H. Clifford and 

 R. G. Fargher have been examining the distillate 

 from large-scale experiments upon the treatment of 

 cotton with sodium hydroxide and superheated 

 steam, conducted by the Bleachers' Association, Ltd. 

 (Journal of the Textile Institute, vol. xiv. No. 5, 

 May 1923). Methyl alcohol and acetone were the 

 main volatile products isolated, a fact which supplies 

 additional evidence for the presence of pectin in the 

 cotton hair, as F. Tutin has shown {Biochem. Journ., 

 vol. 15, 1921) that the alkaline hydrolysis of pectin 

 yields both these substances. 



X-RAY Installation for Veterinary Work. — 

 The Research Department, Woolwich, has published a 

 description of an X-ray equipment, designed and 

 constructed at Woolwich, which has been installed 

 in the Army Veterinary School at Aldershot (R.D. 

 Rep. No. 56). It consists of a large teak table-top to 

 which the animal can be strapped while in the vertical 

 position. The X-ray tube box is mounted on a 

 carrier which enables it to be moved into any position 

 relative to the animal, and the examination may be 

 made or radiographs taken with the animal in the 

 upright position. Alternatively, the table-top may 

 be rotated and moved on rollers so as to bring the 

 animal into the horizontal position over a supporting 

 table. The X-ray tube used is of the standard 

 Coolidge type, completely enclosed for protection in 

 a lead box, and the generating set is designed to supply 

 currents up to 20 milliamperes continuously at 150,000 

 volts. Full details of the apparatus are given. 



Industrial Psychology in Coal Mining. — To 

 attempt to teach a coal miner how to use a pick 

 seems at first sight as valuable as taking coal from 

 Dover to Newcastle ; but a glance at two memoirs 

 by Dr. C. S. Myers and Mr. E. Farmer in the June 

 issue of the Memoirs and Proceedings of the Man- 

 chester Literary and Philosophical Society is sufficient 

 to show how much is to be gained by investigating 

 scientifically the best way of using such a tool. Mr. 

 Adams and Mr. Stephenson, two post-graduate 

 students of the P.sychological Laboratory of the 

 University of Manchester, have devoted twelve months 

 of their time to the investigation, and have for much 

 of this time lived the life and worked the hours of 



NO. 2806, VOL. 112] 



the miner. As a result, the wielding of the pick has 

 been rendered more continuous and rhythmic and 

 a greater output secured with less fatigue of the miner. 

 The effects of improved lighting and more orderly 

 arrangement of work so that less shovelling has to 

 be done have also been investigated, and the miners 

 themselves have taken a keen interest in the in- 

 vestigation. 



A Mercury Flash-light for Photography. — 

 In the Proceedings of the Physico - Mathematical 

 Society of Japan for June there is reprinted a paper 

 from the Japanese Journal of Physics by Kyoji 

 Suyehiro on an " Electrically deflagrated Mercury 

 Filament as a Flash-light for Instantaneous Photo- 

 graphy." In investigations on the rolling of model 

 ships and the vibration of structures, photographs of 

 rapidly moving objects were desired. Prof. Anderson's 

 experiments on electrically deflagrated wires as a 

 source of light led to a trial of this method with fine 

 tin and copper wires, but the results were not en- 

 couraging. Filaments of mercury were tried with 

 success. Mercury is sucked up into a glass capillary 

 tube, and in each end of the tube a " hair wire " is 

 secured with sealing-wax. Thus filaments of any 

 size are easily prepared. The duration of the flash 

 is shorter as the filament is reduced in length and 

 diameter, and it is also affected by the thickness of 

 the wall of the tube. The most intense light is given 

 out by the mercury arc lit just after the explosion. 

 The paper is illustrated with photographs of flashes, 

 results of testing their duration by means of a rotating 

 disc with radial lines on it, and applications of the 

 method. 



Manufacture of Water-Gas. — The Fuel Research 

 Board of the Department of Scientific and Industrial 

 Research has just issued, in its Technical Paper 

 No. 6, a record of experiments at H.M. Fuel 

 Research Station, Greenwich, on the " Comparison 

 of some Methods of running Water-Gas Plant " 

 (H.M.S.O., 25. net). The manufacture of water- 

 gas from coke is of great economic importance, 

 and the accumulation of carefully ascertained data 

 is correspondingly valuable. Observations were 

 recorded on the behaviour of cokes of different origin 

 when used in the generator (of the Humphreys and 

 Glasgow pattern), and the paper deals also with four 

 gasification tests with varying depths of fuel bed. 

 The first three were made on the Dellwik-Fleischer 

 system — with shallow beds of depth 3 ft. 6 in. to 4 ft. 

 and varying rates of steaming. The fourth was made 

 with a deeper bed on the system recommended by 

 the makers. All tests were made on the same coke. 

 The observations in the tests are given very fully 

 in tables of weight and thermal balances, tempera- 

 tures, and rates of gas production. The thermal 

 efficiency of the generator was found to reach 59-9 

 per cent, in the Dellwik-Fleischer system and 57-8 

 per cent, under the normal regime, when no deduction 

 was made for heat losses and expenditure in generating 

 the power employed in the process. These deductions 

 depend naturally on the efliciency of the auxiliary 

 plant, and might depress the efficiency on certain 

 conditions assumed, e.g. in the fourth test to 52-8 

 per cent. The greatest thermal loss occurred in the 

 heat carried by the "blow gas" which lay in the 

 four tests between 20 and 30 per cent, and sufficient 

 theoretically to generate 80 to 130 lb. of steam per 

 1000 cu. ft. of water-gas made. This report may 

 usefully be read in conjunction with the Sixth, 

 Seventh, and Tenth Reports of the Gas Investiga- 

 tion Committee of the Institution of Gas Engineers 

 published in 1921, 1922, and 1923, which give a more 

 detailed study of the water-gas process in its various 

 modifications, as operated in towns gasworks. 



