266 



NATURE 



[November 5, 1914 



parture from its initial simplicity in order to meet 

 special conditions. Prof. Coker read a paper on 

 the stress distribution in short compression members. 

 By means of a transparent specimen and polarised 

 light, the peculiar stress distribution due to the com- 

 pression plates being of different material from the 

 specimen was illustrated. It was shown that approxi- 

 mately pure compression stress can be obtained if 

 both are of the same material. Sir Oliver Lodge 

 read a paper on the artificial electrification of the 

 atmosphere, in which he dealt especially with the pro- 

 duction of rain by the direct electrification of the 

 clouds. The proposal was adversely criticised by Dr. 

 Simpson, of the Indian Meteorological Department, 

 and by Mr. Hunt, the Commonwealth Meteorologist. 

 It was pointed out that clouds are very poor con- 

 ductors, hence the difficulty of giving them an electric 

 charge, and, moreover, that the clouds are often very 

 highly charged, as shown by lightning discharges, and 

 yet without causing- rain. 



The third day was devoted to a joint discussion 

 with the Agricultural Section on irrigation, opened by 

 Prof. Luiggi, of Rome, with a very interesting paper 

 on irrigation works in Italy. The author showed that 

 irrigation and ceaseless toil had transformed large areas 

 of arid land into smiling- gardens. He went very fully 

 into the financial aspect of the question, showing that 

 irrigation schemes require Government support, and 

 are not suitable for private enterprise. He described 

 the engineering features of several of the large 

 schemes now being developed in Italy. A paper on 

 somewhat similar lines, entitled " Irrigation in Vic- 

 toria," was read by Mr. J. H. Dethridge. Papers 

 were read by Mr. Ferrar on the fertility of lower 

 Egypt, and some factors controlling the growth of 

 cotton. 



The Sydney meeting opened with the presidential 

 address on stress distribution in materials. The presi- 

 dent. Prof. E. G. Coker, discussed the various experi- 

 mental methods, dealing especiallv with two, viz., 

 the measurement of local temperature rise due to 

 strain, and the application of polarised light to trans- 

 parent test-pieces. Mr. A. B. Wade read a paper on 

 irrigation in New South Wales, in which, after dis- 

 cussing the rainfall and physiography of the State, he 

 described the irrigation schemes now in hand, 

 especially that in the Murrumbidgee area. He also 

 described the construction of the great Burrinjuck dam. 

 Prof. Luiggi showed a large number of lantern 

 slides illustrating the works carried out under his 

 direction in Tripoli since the Italian occupation ; these 

 include lighthouses, harbours, waterworks, railways, 

 etc. He emphasised the fertility of a great part of the 

 country, and pointed out that it was a great grain 

 producer in the days of the Roman Empire, and that 

 with irrigation and development it should once more 

 become a prosperous agricultural country. Mr. T. W. 

 Keele discussed the Nile flood records between a.d. 641 

 and A.D. 145 1, in which he claims to have found a 

 periodicity of seventy-six years and suggests a connec- 

 tion with Halley's comet. Prof. Dalby described 

 the new engineering laboratories of the City and 

 Guilds (Engineering) College, which are at present 

 nearing completion. 



On the second day Mr. Bradfield read a paper on 

 the new electric metropolitan railway, for which 

 Sydney is seeking Parliamentary sanction. The 

 scheme includes a bridge of 1600 ft. span across the 

 harbour, and the total estimated cost of the whole 

 scheme is 17,000,000?. A paper was read by Mr. 

 Adams on the Australian ports in relation to modern 

 shipping, in which the author discusses the great 

 demands made on the port authorities by the increased 

 length and draught of modern ships and the conse- 

 quent outlav which neutralises to some extent the 



NO. 2349, VOL. 94] 



saving effected by the increased capacity of the ships. 

 The new wharf arrangements at Sydney were 

 described. 



Dr. Rosenhain followed with a paper on the distri- 

 bution of phosphorus in steel, in which, after describ- 

 ing a new reagent (ferric chloride with small quan- 

 tities of copper and tin chlorides) for tinting the 

 surface and thus revealing the want of uniformity in 

 the distribution of the phosphorus, he showed a 

 number of photomicrographic slides. Prof. Hudson 

 Beare described tests which he had made on two 

 petrol fire-engines, and also on the resistance offered 

 to the flow of water by canvas fire hose. 



On the last day of the meeting Prof. E. G. Coker 

 read a paper on the temperature cycle in heat engines, 

 describing a method of obtaining records of the tem- 

 perature cycles in gas-engine cylinders by means of 

 thermo-junctions operating an Einthoven galvano- 

 meter. Prof. Thornton followed with a paper on the 

 lost pressure in gaseous explosions, in which he sug- 

 gested that the difference between the calculated and 

 measured maximum pressure ma}' be due to the 

 sudden efi^ect of the forces of cohesion in converting 

 translational into rotational energy at the moment of 

 formation of the molecule. A second paper was read 

 by Prof. Thornton on the limiting conditions for the 

 j safe use of electricity in coal mining, in which he 

 j discussed the danger of explosion from electric sparks 

 under various conditions. Mr. Balsillie contributed a 

 paper describing the system of radio-telegraphy with 

 which his name is identified, and which has been 

 adopted by the Australian Government, the chief 

 features of which are that electrostatic coupling is 

 employed between the oscillatory circuit and the aerial, 

 and that a gap is employed with a very powerful air- 

 blast, which, it is claimed, gives a unidirectional spark 

 and consequent quenching after a semi-period. In a 

 paper on the capacity of radio-telegraphic aerials, Prof. 

 ' G. W. O. Howe described a method of calculating 

 j rapidly the capacity of any type of aerial. 



Two reports were presented by research committees ; 

 that by the committee on stress distributions in 

 engineering materials consists mainly of a review and 

 bibliography of the experimental methods of investi- 

 gating the subject, especially the application of 

 polarised light to transparent test-pieces. A number 

 of the committee are engaged on work which is not 

 yet completed. A stock of 3 tons of standard steel has 

 been obtained so that all members ma}' work on the 

 same material and thus enable their results to be 

 correlated. 



The report of the committee on gaseous explosions 

 summarises previous reports and discusses the 

 measurement of the temperature in gas-engine 

 cylinders, especially the method employed by Profs. 

 Callendar and Dalby at the City and Guilds (Engineer- 

 ing) College. 



A joint discussion between Sections A and G on 

 wireless telegraphy was held at Sydney. Sir Oliver 

 Lodge, who opened the discussion, reviewed the 

 various explanations put forward to account for the 

 transmission of signals around the curvature of the 

 earth, and the variations due to the alternation of 

 light and darkness. Mr. Balsillie, the Commonwealth 

 wireless expert, communicated some very striking 

 observations ; he had found that with a wave-length of 

 600 metres the ranges by day and night were 450 and 

 2000 miles respectively, and that by increasing the 

 wave-length the day-range was increased while the 

 night-range remained unchanged. Enormous varia- 

 tions in the day-range were produced by small changes 

 in the wave-length, e.g. from 600 to 800 metres. The 

 long range at night was obtained equally well over 

 land or sea, which suggested that the waves travelled 

 through the upper atmosphere and not in proximity 



