Sept. 14, 1 888.] 



SCIENTIFIC NEWS. 



297 



stone (Secretary), Professor Armstrong, Mr. Stephen Bourne, 

 Miss Lydia Becker, Sir John Lubbock, Bart., Dr. H. W. Crosskey, 

 Sir Richard Temple, Bart., Sir Henry E. Roscoe, Mr. James Hey- 

 wood, and Professor N. Story Maskelyne, appointed for the purpose 

 of continuing the inquiries relating to the Teaching of Science in 

 Elementary Schools, was then read. 



Mr. Edward J. Wathekston (London) next read a paper on 

 The Industiial Education of Women Abroad and at Home. 



Miss Helen Blackburn read a paper upon Irishwomen's Indus- 

 tries. 



Mrs. Palmes Hallett said Miss Blackburn's paper touched 

 upon the highest question of political economy. All the efforts 

 referred to had been made by ladies of the landlord class. 



Miss Sharman Crawford, as one who had been intimate with 

 the people in the South of Ireland for twenty years, said she had 

 every reason to speak well of their industry and honesty. They 

 could only compete with machinery by peoDle working for starvation 

 ■wages. 



The discussion was continued by Mr. Stoor. 



The following papers were then read : — 



Economy in Education and in Writing. By Mr. Eizak Pitman, 

 Bath. 



Education : a Chapter of Economics. By Mr. T. W. Dunn, M. A. 



Agricultural Eiucation. By Professor James Long. 



MECHANICAL SECTION. 



{Continued from p. 271.) 

 Saturday, September 8th. 

 Dr. Pole, F.R. S., presiding. 



Mr. J. Gordon (for Mr. Siemens) read a paper on Rolling Seam- 

 less Tubes from Solid Bars or Ingots, by the Mannesmann Process, of 

 which the following is an abstract : — 



The author referred to the circumstance that steel and toughened 

 glass, though specially suitable, on account of their high qualities 

 and strength, for use in the arts, had been somewhat neglected, 

 owing to the difficulty of welding and cutting them. Attention was 

 next drawn to the combination of strength with lightness which the 

 tubular form admits of, and to the extensive use of tubes in con- 

 struction which is likely to follow from a simple means of producing 

 them. The different kinds of rolls hitherto empbyed, which are 

 classed as the longitudinal, circular, and intermediate, were passed 

 in review, and the process which forms the subject of the paper was 

 then described. In the Mannesmann process a certain relation 

 1 between longitudinal and rotary motion is maintained, so adjusted 

 or each material to be worked, that a twist is imparted to the fibre 

 resulting in great strength and toughness of the manufactured 

 product. The following was the mode of manufacture : A bar is 

 placed between conoidal rolls, where the diameter and therefore 

 the velocity are least, and is gradually drawn forward into contact 

 with those portions of the rolls which travel more and more rapidly. 

 The rolls are so set that the space left between them for the 

 passage of the bar decreases slightly, so as to cause a certain 

 amount of material to be shifted. The action of the rolls prevent- 

 ing this material from being taken from the outside of the bar, it is 

 consequently drawn from the interior, a hollow being first produced, 

 and then a tube. A mandril may be employed to finish and smooth 

 the interior and to enlarge the diameter of the tube. That the 

 mandril is not required in the manufacture is proved by stopping 

 tin action of the rolls while the bar is passing through them, and 

 breaking off the bar where the hollow is just commencing to form ; 

 the metal inside is found to be crystalline and bright, as before 

 being cut there is a vacuum within the hollow, no air, of course, 

 entering during the process of manufacture. 



Several questions having been asked — 



Sir Frederick Bramwell, F. R.S., spoke in favour of the adop- 

 tion of the process, as possessing special advantages from a com- 

 mercial point of view. 



Colonel Cunningham, R.E., and Professor Hele Shaw, 

 M.Inst.CE., continued the discussion, and at its close Mr. Gordon 

 replied, giving further explanations in answer to inquiries which had 

 been made, menti oning, amongst other things, that the result of a fre- 

 quent testing had been very satisfactory. 



An interesting paper on the subject of Gaseous Fuel was read 

 by Mr. J. Emerson Dowson, M.Inst.CE., who explained 

 that at the York Meeting of the Association in 1881 he described 

 an apparatus for making cheap heating-gas by passing steam 

 and air through incandescent fuel. Since then the apparatus 

 has been considerably improved, and the gas made in it has 

 been much used, not only for driving engines, but for heating 

 in many industrial processes. The composition of the gas 

 necessarily depends somewhat on the quality of the coal used and 



on the condition of the fire ; the average composition is much 

 the same whether the gas is made at the rate of l,oco cubic feet per 

 hour in a small generator or at the rate of 15,000 cubic feet per hour 

 in a large one. In 188 1 it was necessary for gas-engines to use five 

 volumes of this generator gas for one of ordinary lighting-gas to 

 develop the same power ; since then some important modifications 

 have been made in the Otto engines, and it is now necessary to use 

 only four volumes. In 1SS1 only one engine of 3i horse-power had 

 been worked with the author's gas, but since then "a large number of 

 engines have been worked with it, one indicating over 80 horse- 

 power. For more than four years Messrs. Crossley, the English 

 makers of the Otto engines, have used this gas exclusively at their 

 works for an average of 150 horse-power, and after a careful 

 trial, extending over thirty-five weeks, they found that the fuel 

 consumption was only I 3 lb. per indicated horse-power per hour. 

 At these large works there is no chimney except for the blacksmith's 

 shop. Returns sent by eleven users of Otto engines working regu- 

 larly in different places with the author's gas, and averaging 35 

 horse-power each, show an average fuel consumption of about 1*3 

 lb. per indicated horse-power per hour, which is less than half that 

 required for the best steam-engines of equal power under ordinary 

 working conditions. The results of other tests are given and seeing 

 that all have been obtained under practical working conditions, the 

 record is certainly satisfactory. Many letters have also been received 

 testifying to the ease with which the gas plant can be managed. 

 The author considers himself justified in saying that gas-power is 

 now fairly launched in competition with steam-power, and he 

 thinks, with the late Professor Fleeming Jenkin, that eventually the 

 former will to a great extent supersede the latter. The results 

 already obtained with this gas are good, but the author thinks 

 it tolerably sure that even better results will be obtained when 

 an engine is really designed to give the best effect with 

 generator gas. It is well known that in the Otto engines 

 each new charge of gas is diluted with a portion of the pro- 

 ducts of combustion from the previous charge, and this answers 

 very well for ordinary lighting-gas. But as generator gas, such 

 as - the author's, has only about one-fourth the explosive power 

 of the other gas, it is a disadvantage to dilute it with products of 

 combustion, and he feels confident that sooner or later makers of 

 engines will find it expedient to design all engines of large power 

 specially for cheap generator gas. The best fuel to use for makirg 

 the gas is anthracite, as it does not yield tar or other condensable 

 products, and does not cake in the generator. Ordinary gas-ct ke 

 can also be used with certain precautions. 



Several instances are given of the use of this gas for heating of 

 various kinds. At the Gloucester County Asylum it has been used 

 daily for about five years. All the kitchen work for the staff.and 

 inmates is done with it, and there is no ordinary fire in the kitchen ; 

 about three hundred quartern loaves are baked with the gas every 

 day, at a cost of about one shilling only for fuel. The gas is also used 

 for two 12 horse-power (nom.) Otto engines, which pump water and 

 drive a dynamo for electric lighting. 



On the Continent several firms use this gas for singeing silk 

 yarns and textile fabrics. It is also used by several linen manufac- 

 turers in the north of Ireland for steutering, which they 

 formerly did with hot air. The cost of the gas somewhat depends 

 on that of the fuel ; but speaking generally, the equivalent of 1,000 

 cubic feet of ordinary lighting-gas costs from sixpence to one shilling. 

 Sir Frederick Bramwell said the subject dealt with in the 

 paper was one in which he was much interested, for any invention 

 which tended towards the method of driving engines by heat in- 

 stead of by steam was most desirable. In his paper the author had 

 alluded to some statements he (Sir Frederick Bramwell) had made 

 in his address as President to the members of the Institution of Civil 

 Engineers, and they were certainly very striking. He deplored the 

 fact that in consequence of coal and slack being so cheap, people 

 were indifferent to any proposal to substitute an improved method 

 of using it. To him it was a terrible thing that they should be 

 wasting by the extravagant use of coal the inheritance of those who 

 were to come after them, and he therefore thought that anything 

 which could be done to put a stop to it ought to be encouraged. 

 The writer of the paper had hardly given credit to the steam-engine 

 trials which he bad referred to in his address the other evening. There 

 was no doubt the engine was in the best order on that occasion, and it 

 was worked by a very skilled person, who did not hesitate to display 

 his great interest in the tiial by turning up his sleeves and 

 himself performing the duties of stoker. He (Sir Frederick) thought 

 that the theory of the gas-engine was a good one, and that its results 

 when worked with cheap gas would be satisfactory he did not doubt. 

 In proof of this he had recommended its adoption instead of steam 

 in a case where it was very desirable to reduce the fuel consumption. 

 He looked forward most hopefully to the outcome of the subject 

 brought before them. 



