652 



NA TURE 



[October 22, 1908 



when three papers were read. The first, by Mr. J. 

 Brown, F.R.S., and Prof. Maurice Fitzgerald, described 

 a series of experiments they had carried out on rotating 

 discs. The discs were rubber — one solid, 12 inches in 

 diameter, with its thickness tapering from 2J inches in 

 the middle to \ inch at the edge, and the second 12 inches 

 in diameter, |-inch thick at the edge, and 3 inches thick 

 in the middle, where it was pierced with a li-inch hole. 

 In the first disc the thickness varied uniformly from the 

 centre to the edge ; in the second the cross-section of the 

 disc formed a hyperbolic curve. The object of these ex- 

 periments was to determine, by measurement of the strains 

 set up when the discs were rotating, whether the formulae 

 usually employed in the calculation of stresses in the 

 revolving discs of steam turbines were reasonably trust- 

 worthy. The discs were carried at the lower end of a 

 vertical shaft, which was driven at a high speed by an 

 electric motor ; photographs were taken of the revolving 

 disc, and strain measurements were thus possible. As a 

 result of their experiments, the authors were of opinion 

 that the ordinary formula did not give results which were 

 approximate enough for ordinary use. Of course it is 

 well known that these formulae are only approximate, but 

 it is doubtful whether the e.xperiments of the authors are 

 sufficiently conclusive to prove that the formulfe are as 

 untrustworthy as was suggested in the paper. 



The next paper was by Mr. Douglas Fox, on general 

 urban and interurban transportation and rail-less electric 

 traction. This paper contained, in the form of tables, an 

 exhaustive analysis of the costs, working expenses, receipts, 

 &c. , of some seventy-one tramway installations in the 

 United Kingdom. The examples selected by the author 

 embraced towns having combined generating stations for 

 traction and electric lighting, and towns which had 

 separate generating stations for their tramways and their 

 lighting. Details were also given of several installations 

 of electric road traction on the Continent, where over- 

 head wires were employed and there were no rails ; one 

 of the latest of these was at Mulhausen, in Alsace, where 

 it had been decided to adopt rail-less electric cars in order 

 to connect up the suburbs with the existing electric tram- 

 ways in the city proper. Mr. Fox was of opinion that 

 in many of the municipal tramways ordinary business 

 principles had been neglected and that the public had 

 been allowed to travel at the expense of the ratepaver, 

 fares being too low to allow, after working expenses had 

 been defrayed, of the setting aside of a reasonable sum 

 for depreciation and renewal. 



The section concluded its proceedings with a paper on 

 the strength of solid cylindrical, round-ended columns, by 

 Prof. W. E. Lilly. In previous papers by this author the 

 importance of secondary flexure and its influence on the 

 strength of columns had been demonstrated, and as a 

 result of his researches he had suggested the revision of 

 the formula at present in use for the design of columns. 

 The _ modified formula which the author "had suggested 

 required certain constants, and the object of the experi- 

 rnents described in the present paper was the determina- 

 tion of the value of these constants. Experiments had 

 been carried out on columns of cast tool steel, Bessemer 

 steel, mild steel, wrought-iron, and cast-iron, and the 

 results obtained were given by the author in the form of 

 a table ; the constants in this table were for use with 

 the well-known Rankine Gordon formula. 



AGRICULTURE AT THE BRITISH 

 ASSOCIATION. 



'T'HE Dublin meeting of the British Association was 

 marked by the resuscitation of the subsection of 

 agriculture, which, after a previous temporary existence 

 as a dependent of botany and some fitful appearances as 

 a branch of chemistry, now became associated with 

 economics. As was appropriate in these circumstances, 

 and with Sir Horace Plunkctt as president, the work of 

 the subsection was mainly concerned with the economic, or 

 rather with the sociological, side of agriculture. 



Thursday morning was occupied with the presidential 

 address, in which, at the outset. Sir Horace said that he 



NO. 2034, VOL. 78] 



spoke neither as a man of science nor as a practical 

 farmer, but as a man of affairs whose way of life had 

 brought him into close touch with the conditions, human 

 and material, which it will be the aim of the subsection 

 to improve. His purpose was to establish the claim of 

 agriculture to a new position in the domain of science, for 

 reasons that are primarily neither scientific nor practical, 

 but political. It does not appear to have been sufficiently 

 considered how far the ethical and physical health of the 

 modern city has been due to the constant intlu.x of fresh 

 blood from the country. At present the town makes an 

 irresistible appeal to the spirit of enterprise, to the grow- 

 ing craving lor excitement, to the desire to live where 

 there is most life. But sooner or later, if the balance of 

 trade in this human traffic be not adjusted, the raw 

 material out of which urban society is made will be 

 seriously deteriorated, and the national degeneracy will be 

 properly charged to those who failed to' foresee the evil 

 and treat the cause. H the problem has not yet received 

 the proper attention at the hands of the sciences, its 

 urgency is growing in the public opinion and stirring the' 

 centres of government. The influence of the British 

 Association upon national life must depend, not upon its 

 highest achievements in the region of pure science, but 

 upon the degree in which it establishes and maintains a 

 mutually helpful relationship between science and pro- 

 ductive effort. He did not suggest that agriculture had 

 not shared in the benefits with which science, physical and 

 social, had richly endowed the whole field of industrial 

 effort, urban and rural. But there is surely a marked dis- 

 parity between the attention given to urban and rural 

 affairs by those engaged in the application of science to 

 the advancement of mankind. A great gulf, no doubt, 

 separates the agriculture of Vergil from that of Sir John 

 Lawes, but how insignificant it is beside the ocean of 

 knowledge which stretches between Archimedes and Lord 

 Kelvin. In his work in Ireland he had been in the habit 

 of employing a rough formula to indicate the three-fold 

 character of the constructive work that is needed in rural 

 life — better fanning, better business, and better living. To 

 each of these three divisions the sciences ought to be 

 most helpful ; the natural sciences to the first, economic 

 science to the second and third, educational science to all 

 three. Sir Horace then proceeded to emphasise in greater 

 detail the necessary part played by research, by economic 

 investigation, and by education in rural reconstruction. 

 Lastly, he proceeded to plead for the more adequate 

 recognition of agriculture by the association ; he demanded 

 that it should be accorded the dignity of a section instead 

 of being left in its present unstable condition, without any 

 organisation to secure the continuity of even a subsection 

 from year to year. The association might thus help to 

 " counteract tendencies through which preceding empires, 

 after they had arrived at a stage very similar to that which 

 we occupy to-day, hastened to their decline and fall. Be 

 this as it may, it would hardly be an exaggeration to say 

 that modern civilisation has joined the rural exodus. Let 

 it be the high aim of the British Association, leading 

 science and practice hand in hand, to call it back." 



In the afternoon following the presidential address, Sir 

 Oliver Lodge described some of the experiments, which 

 are being made on a large scale near Worcester, on the 

 effects of a high-tension electrical discharge over a growing 

 crop. While carefully guarding himself from any specula- 

 tion as to whether the seat of the action was in the soil 

 or the plant, whether a stimulus action or an inflow of 

 energy, there seemed to be a positive result which was 

 quite outside the domain of experimental error. Mr. 

 J. H. Priestley, who has been associated with the experi- 

 ments, gave some further details, and explained the in- 

 vestigations he had in hand to elucidate the nature of the 

 action of the electricity. Then followed a paper by Prof. 

 J. R. Campbell, of the Irish Department of Agriculture, 

 in which he lucidly explained the educational work of that 

 department, where the following of a carefully considered 

 policy has achieved much happier results than the wasteful 

 English method of leaving each county council to go as 

 it pleases. Education was also the text of the next paper, 

 by Dr. Carroll Dunham, of Harvard, in which he com- 

 pared the systems of agricultural education prevailing in 

 the United States, according as their aim was to prepare 



