196 



NATURE 



[July 7, 192 1 



Mr. Alexander Ross laid down as propositions for 

 discussion that on our railways the 6-ft. space should 

 be widened to 7 ft. ; if there are more than two lines 

 of rails, the space between the original pair of rails 

 and additional rails should not be less than 11 ft. 6 in. 

 No overhead structure should have less clear head- 

 way than 15 ft. 6 in. above the top surface of the 

 rails. No structure higher than 2 ft. 6 in. above rail- 

 level should be nearer to the edge of the nearest rail 

 than 5 ft. 



Mr. Oswald G. C. Drury described the use of the 

 IngersoU cement-gun in carrying out repairs on the 

 Cliftonville tunnel. The next few months will show 

 the value of this method of grouting, but Mr. Drury 

 thinks that the method is a practical success from the 

 point of view of stability and speed, although the 

 commercial value has yet to be thoroughly tested. 



Mr. William W. Grierson gave particulars of the 

 now extensive use of reinforced concrete on British 

 railways. The use of fence-posts of this material is 

 largely on the increase. Various designs of reinforced 

 concrete sleepers have been experimented with, but 

 none are successful under heavy and frequent traffic 

 at high speeds. 



The important question of the best way of pro- 

 tecting reinforced concrete from marine deterioration 

 was introduced by Mr. Francis E. Wentworth- 

 Sheilds. Our experience of this material for mari- 

 time structures now extends over twenty years, and 

 there have been several failures. These are owing to : 

 (a) The concrete has become softened bv the chemical 

 action of the sea-water. (?>) Th > concrete has scaled 

 off owing to the action of frost, (r) The concrete has 

 worn off by attrition by travelling shingle and stones, 

 (d) The concrete has split and cracked by the rusting 

 of the enclosed steel and its consequent increase in 

 volume. The last is the most common type of 

 failure. 



Mr. George E. W. Cruttwell presented an interest- 

 ing note on the use of a model for investigating the 

 movements in the River Thames between Teddington 

 and Shoeburyness. TTie first model of this kind was 

 employed by Prof. Osborne Reynolds, and the present 

 improved model gave very good results. Mr. Crutt- 

 well suggests that the greater pi>rt of the model and 

 the whole of the working apparatus could be adapted 

 for experimenting with other esruaries at a trifling 

 cost, and that it would be most advantageous to the 

 engineering profession if the National Physical 

 T-aboratorv or some similar institution could install 

 the necessary apparatus, which could then be adapted 

 to suit anv particular case. The cost of the Thames 

 model was about '^00/., and a moderate fee would 

 cover the cost of the necessary adaptations and 

 investigations. 



Tn dealing with the bearing power of soils Mr. 



Arthur L. Bell made reference to the various theories 

 of earth-pressure. Advance in earthwork problems 

 had been, in the main, due to individual experiment 

 and speculation, and Air. Bell considers that the best 

 hope for the future lies in the encouragement and aid 

 of individual inquiry. Engineers seek a sound and 

 preferably simply theory which can be successfully 

 applied, not to one only, but to all the nuiltitudinous 

 varieties and conditions of soil 



The influence of the automatic and semi-automatic 

 machine on the skill and resourcefulness of the 

 mechanic and operator was the subject of a note con- 

 tributed by Mr. Arthur H. Hall. Such machines 

 are set ready for work by a skilled mechanic and 

 operated by another person. Mr. Hall considers that 

 the designer has precluded the operator from the dis- 

 play of resource, but that a reasonable amount of skill 

 is required. The mechanic must display great re- 

 source, the amount varying with the degree of respon- 

 sibility allotted to him by the management in the 

 matter of design and lay-out of tools. His skill in 

 making these is of the kind usually expected of a 

 highly trained workman, but in setting them up he 

 may exhibit qualities not readily capable of compari- 

 son with those required in other work. 



Sir Robert Hadfield presided in the mining and metal- 

 lurgical section, ruid said that the world was literally 

 hungering at the present time for a hundred million 

 tons of iron and steel. Iron was the standard of all 

 mcxlern comfort, and to economise in its use meant to 

 reduce our civilisation. Take away this metal, and 

 the world would relapse into almost a state of bar- 

 barism. 



Dr. John W. Evans introduced the subject of the 

 employment of water-power in the development of 

 the mineral industry. During the war there was a 

 remarkable advance in Sweden, where the number 

 of electric furnaces increased from eight in 19 14 to 

 twentv-eight in iqiS, and the output of pig-iron ob- 

 tained from them increased from 5786 tons in 191 1 to 

 75,684 tons in T918. The day is at hand when e!ec- 

 trolvtic methods will enable metals to be extracted 

 with commercial success from ores which are too 

 poor to be dealt with by smelting operations. 



Fabricated ships were dealt with in notes bv Mr. 

 Maurice E. Dennv and Mr. John C. Telford. These 

 notes consider the problem from the labour-saving 

 point of view. The premier requirements to make 

 fabricated ship construction a success are several 

 vessels all alike, standardised so as to make the detail 

 reproduce itself many times' over; also (a) careful 

 work in the drawing office and template loft, (b) 

 accurate workmanship in the shops, (r) close inspec- 

 tion, and (</) the provision of ample means for check- 

 ing the several parts with jigs and templates as the 

 work proceeds. 



Obit 



Abbott H. Thayer. 



ALL naturalists, and especially those of the 

 English-speaking- world, will learn with 

 great regret of the death of the distinguished and 

 original artist-naturalist, Mr. Abbott H. Thaver, 

 announced in Science for June 10. Many of us 

 will lament the loss of a dear friend who sym- 

 pathised with our sorrows and difficulties as if he 

 had been one of us, and, long before his country 

 joined the struggle on behalf of freedom and 

 civilisation, came to England in the hope that he 

 could induce the authorities to accept his help in 

 the methods of " camouflaee " by land and sea. 



NO. 2697. VOL. IO7J 



uary. 



Thayer's great fundamental discovery was of 

 course the interpretation of the white undersides of 

 animals as the elimination of shadow by counter- 

 shadino". I once asked him how he came to think 

 of it, and his answer showed that the discovery 

 sprang from the artist side of his nature. He 

 observed, he said, that animals in the wild state 

 were elusive and ghost-like, and that when the 

 artist wished to paint them so that they might be 

 easily seen in the picture be had to employ an 

 unnatural illumination or to represent them sil- 

 houetted against the sky. He was thus led to 

 investigate, and finally to discover, the cause of 



