September 5, 1907] 



NA TURE 



4S5 



the question was one of cost, and as the first-class ores 

 bi;c;mie exhausted and prices rose, the second-class ores 

 would prove remunerative. 



Colonel Parrett tooli an optimistic view, and referred 

 to the vast quantities of rich ore in Australia and the 

 Transvaal. 



The president, in closing the discussion, looked for- 

 ward to Australia, with its vast coalfields and easy trans- 

 port, becoming the great centre of iron production. 



Mr. W. G. Fearnsides, in describing the pisolitic iron 

 ores of North Wales, showed that they were not, as 

 formerly supposed, characteristic of certain geological 

 horizons. 



K paper by Prof. J. Joly, on the distribution of radium 

 in the rocks of the Simplon Tunnel, raised many questions 

 of great interest. From the examination of thirty-six 

 typical samples taken from various points in the tunnel, 

 he showed them to contain varying amounts of radium, 

 and, taken together, they were sufficient to disturb any 

 forecast of the temperature which under normal conditions 

 would be encountered at the level of the tunnel. The 

 presence of radium in the sediments, in hitherto un- 

 suspected quantities, raises the question whether its 

 presence may not be a factor in the events attending 

 mountain building. The shifting of radium and its parent 

 elements by denudation must be regarded as a convection 

 of thermal energy, and result in the shifting of areas of 

 high temperature and crust-weakness from age to age as 

 the site of sedimentary accumulation changes. 



The chief papers dealing with pala;ontology were by 

 Mr. F. Raw, on the trilobite fauna of the Shineton shales 

 and on the development of Olenus salteri ; the paljeontology 

 of the North Derbyshire coalfield, by Mr. A. R. Horwood ; 

 and reports from various research committees. 



The Carboniferous Zones Committee, after several years 

 of useful work, presented its final report, but the work, 

 which has been carried on with so much vigour and 

 success by Dr. Wheelton Hind and others, will be con- 

 tinued by another committee of which Dr. A. Vaughan 

 is secretary. 



The committee appointed to investigate the fossiliferous 

 drift deposits at Kirmington and at various localities in 

 the East Riding of Yorkshire has devoted its energies to 

 a careful examination of the mammaliferous gravels at 

 Bielsbeck, in the Vale of York. The deposits occupy a 

 depression in the Keuper marls, and have accumulated 

 in a boggy hollow on an old land surface. None of the 

 material excavated can be assigned to the direct agency 

 of ice, and there is no evidence available which will 

 definitely fix its age relatively to the Glacial period. 



.\ new section of glacial gravels in Holderness was 

 described by Messrs. Sheppard and Slather. They are 

 considered by the authors to represent part of the terminal 

 moraine of the North Sea ice sheet. 



The pre-Devonian beds of the Mendip Hills were re- 

 ported on by a committee appointed to examine their 

 fossil contents and their relations to a peculiar coarse, 

 ashv conglomerate found in the neighbourhood. 



Mr. Lomas described the occurrence of a remarkable 

 bed of peat found during excavations in the Union Dock, 

 Liverpool. The chief interest of the deposit lies in the 

 fact that the peat is composed of marine plants encrusted 

 with polyzoa, hydrozoa, serpulae, and other marine 

 organisms. 



Mr. A. R. Horwood read a paper on a hitherto un- 

 noticed section of the Amalthetis spinatus zone in the 

 Middle Lias at Billesdon Coplovv, Leicestershire, and some 

 notes on the ancient volcanoes of Basutoland were sent 

 by the Rev. S. S. Dornan. 



.A catalogue of destructive earthquakes was submitted 

 by Prof. J. Milne. Taking only those which have done 

 structural damage, he finds that between the years 1150 

 and 1250 A.D. large earthquakes were very frequent, and 

 another great increase commenced about the year 1650, 

 and is still in progress. 



Prof. Freeh in a subsequent paper showed the part 

 which earthquakes have played in mountain building. 



Reports on the .Anglesey rocks, bv Mr. E. Greenly, and 

 on erratic blocks, by Prof. P. F. Kendall, completed the 

 paper* read before the section. J. L. 



NO. 1975. '^'OL- 76] 



ENGINEERING AT THE BRITISH 

 ASSOCIATION. 

 TN accordance with its usual custom, the section did not 

 -'■ meet on the opening day until 11. 15 a.m., in order 

 that members might have an opportunity of attending the 

 presidential address in Section A. 



The proceedings of Section G began with the delivery 

 of his presidential address by Prof. Silvanus Thompson, 

 which dealt mainly with the subjects of the history and 

 development of electric motive power, and the education 

 and training of engineers. After the vote of thanks to the 

 president, Mr. Dugald Clerk read a paper on the present 

 position of gas and petrol engines. The author pointed 

 out that experience in the construction and design of 

 large gas engines is gradually accumulating, but that the 

 conditions of work in this country differ in one important 

 respect from those on the Continent. Practically all the 

 large Continental gas engines are operated with blast- 

 furnace gas, while in this country producer gas has been 

 almost exclusively used, and he was of opinion that until 

 the problem of the bituminous fuel producer was solved, it 

 would be difficult to continue to increase the dimensions 

 of gas engines. Mr. Clerk himself has been working for 

 some vears now at the problem of reducing maximum 

 pressures as well as temperatures, without reducing mean 

 pressures, in order that the thickness of the cylinder cast- 

 ings, &c., might be reduced, and that the weight of the 

 engine itself might be made more reasonable for moderate 

 powers ; he has been experimenting with a 50 horse-power 

 engine in order to obtain definite data as to the rates of 

 cooling of the working fluid in the actual engine at 

 different temperatures and pressures, and he showed a 

 verv interesting diagram illustrating his results, and a 

 table of apparent specific heats of the working fluid at 

 varying degrees of temperature which he had worked out 

 from these experiments. This table showed conclusively 

 a rapid increase of apparent specific heat with increase of 

 temperature. From the values of the specific heat thus 

 obtained, Mr. Clerk was able to obtain a curve of heat 

 loss to the sides of the cylinder both for complete double 

 strokes and for partial double strokes at the inner end 

 of the stroke. The paper concluded with a brief dis- 

 cussion of some interesting points in connection with the 

 petrol engine, and especially with the problem of the 

 exhaust gases. The author showed by results of experi- 

 ments on his own motor-car that by adjusting the 

 carburetter he was able to reduce the percentage of CO 

 in the exhaust gases very considerably. 



In the afternoon the members of the section had an 

 opportunity of visiting the works of Messrs. N. Corah 

 and Sons, hosierv manufacturers, where they saw many 

 examples of the most efficient and up-to-date machinery 

 now used in the manufacture of hosiery. The works are 

 extremely well planned, and reflect the greatest credit 

 upon the proprietors, not only for the skill with which 

 the machinerv has been arranged and working costs kept 

 down, but for the great attention paid to ventilation in 

 the workrooms and to the comfort and general well-being 

 of the emplovees. 



Fridav morning, with the exception of a short paper 

 by Prof. B. Hopkinson and Mr. L. G. E. Morse on the 

 gases exhausted from a petrol motor, was entirely devoted 

 to a joint discussion with Section B on gaseous explosions 

 with special reference to temperature. Prof. Hopkinson 

 and Mr. Morse in their paper gave an account of experi- 

 ments which had recently been carried out in the engineer- 

 ing laboratory of Cambridge University on a four-cylinder 

 Daimler engine in order to determine the conditions under 

 which carbon monoxide is formed in an internal-combus- 

 tion motor, and the relation between the composition of 

 the exhaust gases, the strength of the mixture, the power 

 developed by the engine, and the thermal efficiency. 

 These experiments showed that the curve obtained by 

 plotting the thermal efficiency reckoned on the indicated 

 horse-power to a base of petrol consumption had a sharply 

 defined maximum near the point where the consumption 

 was about 2/ioth lb. of petrol per 1000 revolutions, or at 

 the point at which the petrol is just suflicient to be burnt 

 by the available oxygen. The rapid increase in the per- 



