May 12, 19 1 o] 



NA TURE 



325 



jsounds. This has been brought about by mechanically 

 Ituning the disc D and the reed P of the telephone relay 

 Ito the corresponding low note, and by a proper proportion- 

 ling of the volume of air enclosed by the tube B. On other 

 [occasions, during private experiments, the instrument has 

 I been tuned so that nothing but the breathing sounds were 

 audible; the passage of air through the lungs was heard 

 las the roar of the wind through a forest of trees. This 

 (power of discrimination should be of service in allowing 

 the independent examination of various organs of the body. 

 Replacing the telephone head-piece by a transformer, the 

 stethoscope has been joined to the telephone service in my 

 house, and, for the sake of experiment, the sound of the 

 iieart has been transmitted over several miles of telephone 

 line to doctors in various parts of London and to other 

 friends who were interested. All of them reported that 

 the sounds received in the telephone were as loud and 

 dear as when heard locally. The line, therefore, does not 

 appear to produce much loss or distortion. This trial 

 proved that it is now possible for a specialist, say, in 



lighting, education, and public assistance have made for 

 the comfort, health, and enlightenment of the people. 

 Taking increase in wages paid to the worker, and also the 

 increased spending power of these wages, into account. 

 His (jrace quoted statistics showing a net increase, for the 

 period mentioned, of 90 per cent. 



The meeting then proceeded with the reading and dis- 

 cussion of papers, thirteen of which were presented. 

 Owing to lack of time, several of these had to be taken 

 as read. In the case of those actually presented at the 

 meeting, the time allowed to the author for explaining the 

 contents of his paper was in each case ten minutes. The 

 institute is to be congratulated on the high standard and 

 importance of the papers presented, but we think that it 

 will be difficult to maintain this standard unless in future 

 more time is placed at the disposal of the authors at the 

 meetings. 



Mr. D. Selby Bigge, in a paper on the development 

 in the production of electric power, pointed out that con- 

 siderable progress had been made in the cost at which 



London, to examine a patient, say, in the countrj, stetho- | electricitj' can now be produced in iron and steel works 

 ■scopically, and to arrive at a correct diagnosis. ! having at their disposal waste gas, waste heat, and waste 



The instrument must of necessity, to replace the ordinary 

 stethoscope, be more sensitive to sound than the human 

 ear. This is proved by slight noises made in the room 

 "being heard in the telephones as loud noises. In conse- 

 <}uence of this, the apparatus is padded and guarded, so 

 far as is possible, from all outside disturbances, and the 

 patient should be examined in a quiet room. If the instru- 

 ment is provided with a small funnel in place of the tube 

 B, it will pick up and magnify the slightest sound, and 

 ordinary speaking may be increased to a deafening shout 

 in the telephone. Such an instrument, when properly 

 constructed for the purpose, may be of use to those who 

 are afflicted with deafness. 



Fi<;. 8. — Electrical Stetho -cope and Telephone Relay ready for use. 



The relay has been used on the electrophone system, and 

 by its aid, damping the reed with a piece of rubb^, the 

 speaking and music from the theatres are rendered with 

 loudness and greater clearness than it is possible to have 

 on the telephones supplied by the company, and by adding 

 a loud speaker with trumpet the sounds can be heard in 

 the room. 



THE IRON AND STEEL INSTITUTE. 

 'THE annual general meeting of the Iron and Steel 

 ■*■ Institute was held on Wednesday and Thursday, 

 May 4 and 5, at the Institution of Civil Engineers. The 

 retiring president — Sir Hugh Bell — inducted the president- 

 elect, His Grace the Duke of Devonshire. After presenta- 

 tion of the Bessemer medal to Mr. E. H. Saniter, of 

 Rotherham, for scientific services rendered to the iron and 

 steel industry, the Duke of Devonshire gave his presi- 

 dential address. In the course of a long and detailed 

 account of the rise and progress of the coal, iron, and steel 

 industries in this and foreign countries, the president also 

 reviewed the social and economic conditions over the period 

 from 1869, when the institute was founded under the presi- 

 dency of the seventh Duke of Devonshire, to the present 

 time. Conditions of work are now safer and more sani- 

 tarj- ; wages are better, and working hours lighter. 

 Housing is better, and a host of improvements in traffic, 

 NO. 2 I 15, VOL. 



steam. One of the means by which low cost of produc- 

 tion has been attained is the mixed pressure steam turbine. 

 Such turbines differ from exhaust steam turbines in that 

 the latter are intended to derive their supply of steam from 

 engines which run continuously, such as blowing engines 

 and pumping engines. Mixed flow turbines may work with 

 reciprocating engines which are only in action inter- 

 mittently. A continuous supply of steam is obtained for 

 the turbine by adopting a form of regenerative accumulator, 

 the action of which is as follows. The exhaust steam is 

 taken from the engines and mixed with water, both coming 

 to the same temperature. Supposing, now, a drop in 

 pressure of 15 to 2 <^ per square inch to take place in 

 • the accumulator, owing 



to the exhaust steam 

 supply being cut off, the 

 water in the accumu- 

 lator at once gives off 

 vapour, thus keeping up 

 the supply to the turbine. 

 .\ny sudden rushes of 

 exhaust steam from the 

 engine are utilised in 

 storing heat in the accu- 

 mulator, and will be 

 drawn on for supplying 

 the turbine during the 

 next pause in the supply 

 of exhaust steam. 



The turbine is built in 

 stages, one set being 

 designed for the work- 

 ing pressure of the 

 constructed as to give 

 the turbine upon live 

 other set is designed 



existing boilers, and 

 off the full output 

 steam when required ; 



so 

 of 

 the 



S3] 



for the utilisation of exhaust or low-pressure steam received 

 from the accumulator in the case of engines working inter- 

 mittently, or direct from the exhaust of engines running 

 continuously. The low-pressure end of the turbine is also 

 designed to give out the full rating or output upon low- 

 pressure steam alone. Should the full supply of exhaust 

 steam fail from any cause, live steam is automatically 

 admitted to make up the temporarv' deficiency in the 

 e.xhaust steam available. Further, high-pressure steam is 

 admitted when required to the high-pressure stage without 

 the intervention of a reducing valve. To secure efficiency, 

 a high vacuum must be secured, and the selection of a 

 suitable condenser must be carefully considered. Various 

 t)-pes of turbines, gas engines, and electrical installations 

 for steel works are described by the author in the paper. 

 The adoption of any particular system must obviously 

 depend on the circumstances ; each case must be considered 

 on its merits. It is of interest to note that the Duke of 

 Devonshire in his address cited the economy effected last 

 year at the Barrow Works, where the installation of eight 

 gas engines to replace the steam-driven engines produced 

 an immediate saving of 1500 tons of coal weekly. 



•An interesting paper on the cutting properties of tool 

 steel was contributed by Mr. Edward G. Herbert, of Man- 

 chester. It is well known that a high-speed steel tool with 



