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NATURE 



[October 22, 1914 



museum, where local experts provided a full pro- 

 gramme. Mr. R. Etheridge commented on various 

 ethnological exhibits from Australia and New Guinea, 

 being part of the rich collection over which he pre- 

 sides. Mr. S. A. Smith dealt with various anatomical 

 peculiarities of the Australian aborigines. Messrs. 

 Flashman, Hedley, Enright, and Elmore were also 

 to thank for interesting contributions and exhibits, 

 while a great debt is due to Prof. J. T. Wilson, who, 

 despite the severe duties of military censor, managed 

 to arrange for so strongly supported and well- 

 organised a sectional meeting as that of the anthro- 

 pologists at Sydney. 



It has proved quite impossible to do justice here to 

 the multitudinous experiences which, altogether apart 

 from the formal proceedings of the section, have 

 served to make the Australian visit of the association, 

 and of the anthropologists in particular, at once 

 pleasant and profitable in a quite unique way. The 

 unfailing kindness and hospitality shown by our over- 

 seas brethren one and all make it a too invidious task 

 to assign special thanks, and it must suffice, by way 

 of showing due gratitude, to see to it that, in the way 

 of science, Australia's myriad wonders and excellences 

 are henceforth rated at their proper worth. As for 

 the anthropologists in particular, they cannot be 

 accused of having neglected Australia, since it has 

 ever been the happy hunting-ground of the theorist 

 seeking to reconstitute the life of primitive man ; but 

 at any rate it is likely that henceforth the study of 

 Australian problems will proceed more intensively, 

 Inasmuch as the astonishing wealth of the x'Vustralian 

 museums has been realised from near at hand. More- 

 over, we come away feeling that we have left on the 

 spot plenty of men capable of carrying out the best 

 kind of anthropological work, if onlv those in control 

 of ways and means can be induced to make proper 

 provision for a branch of study in which Australia 

 might well aspire to lead the world. 



THE IRON AND STEEL INSTITUTE. 



ONE of the most noteworthy of the papers which 

 was to have been presented at the Paris meet- 

 ing, abandoned on account of the war, describes a 

 new method of heating blast-furnace stoves. It ap- 

 pears from experiments on a stove carried out at the 

 Neunkirchen works of Messrs. Stumm Brothers that, 

 in their ordinary practice, of the total heat put Into 

 the stove about 26 per cent, was carried away In the 

 waste gases and 18 per cent, was lost by radiation. 

 Accordingly the efficiency of the stove was not more 

 than 56 per cent. 



As the author, Dr. Spannagel, points out, it Is 

 almost the universal practice to heat the stove for 

 three to five hours and then send the blast through 

 for one to one and a half hours. Messrs. Pfoser and 

 Strack set themselves the task of finding out why the 

 chequer work gives up its heat to the blast In a so 

 much shorter time than Is required to collect the heat 

 from the waste gases, and they found that It was 

 due to the fact that the velocity of the gases is different 

 In the two cases. Under present conditions, when 

 the temperature of the stoves Is required to be raised 

 the velocity of the gas Is Increased, and this causes 

 the temperature of the waste gas to rise. Hence the 

 waste gas losses are Increased and the efficiency is 

 reduced. The experimenters found, however, that this 

 rule only holds up to a certain point, and that If the 

 velocity is increased still further the temperature of 

 the waste gas not only ceases to rise but begins to 

 fall. The reason for this is probably that with a low 

 velocity gas the molecules flow almost parallel to each 

 other and the friction with the bricks is inconsiderable 

 and consequently it Is only the molecules which flow 

 Tjn oiA"?. VOT.. Qa1 



close to the chequer brick which transmit their heat 

 by direct contact, whereas the remainder Impart their 

 heat slowly by radiation. If now the velocity is in- 

 creased to the usual extent, the friction of the gas 

 molecules against the brick causes some eddying in the 

 outer layer of gas, and the inner particles are partly 

 drawn into movement. The heat transmission is more 

 rapid, but since the gas velocity is greater more heat 

 is carried off unused. By raising the velocities still 

 more the friction betw-een the gas molecules and the 

 brick becomes so great that the particles rebound and 

 Impart their rapid movement to those even in the 

 centre of the current. Accordingly, the violent eddv- 

 ing produced brings all the molecules rapidly in con- 

 tact with the chequer brick, and they give up their 

 heat rapidly. Hence the temperature of the waste 

 gas falls. The principle of the method, therefore, is 

 precisely the same as that of the high-speed boiler 

 designed by the late Prof. Nicholson, and indeed the 

 authors say, " Experiments which have already been 

 made in boiler firing have given particularly favourable 

 results." 



In heating the stoves the velocity of the gas Is 

 brought up to the necessary point by blowing in com- 

 pressed air at a pressure of about 16 in. of water. 

 At the first trial the heating period was reduced to 

 ij hours, " the temperatures of the waste gases and 

 of the blast being 350° C. maximum, and 800° C. 

 respectively, as compared with the former heating 

 period of 4^ to 5 hours, and a waste gas temperature 

 of about 700° C. maximum, the blast temperature 

 being the same." The experimenters have found it 

 advantageous to use highly cleaned gas, since It 

 enables the cross section of the heating passages to be 

 reduced and the surface of the chequer brick to be 

 substantially increased. 



One of the outstanding problems, both of the iron- 

 maker and the steel-maker, has always been the utilisa- 

 tion of the heat contained In slags. It Is not so many 

 years ago that the slags themselves were wasted. At 

 the present day the uses of the various types of slags 

 are many and various, but hitherto their sensible heat 

 has been unutilised. Accordingly, the paper by Mr. 

 W. L. Johnson, of Messrs. Bell Brothers, on this 

 enormously Important Industrial problem, recording 

 as It does the results of tests that have been in pro- 

 gress for four years. Is well worth studying. The 

 principle of the method has been to generate steam 

 by allowing the molten slag to flow Into a suitable 

 generator and to utilise It In an exhaust steam turbine. 

 In the first tests the steam was utilised direct from 

 the generator, but these were abandoned in favour 

 of an indirect method In which a water heater and a 

 heat exchanger were introduced between the primary 

 generator and the turbine. The calandria used was a 

 " Kestner single-effect climbing film evaporator," and 

 consists of two parts, the calandria proper and the 

 separator. A certain amount of sulphur was deposited, 

 but there seems to have been very little corrosion of 

 the tubes of the heater. A vacuum of about 9 in. 

 of mercury was maintained in the separator so that 

 the water boiled at 90-91° C. "With steam from the 

 slag at 100° C. and keeping a temperature In the 

 calandria of 91°, the mean of twenty-two experiments 

 gave 173 gallons of water evaporated per hour, and 

 the average steam per hour condensed In the calandria 

 and heater was 190-2 gallons. The feed water entered 

 the heater at an average temperature of 246° C, and 

 entered the calandria at an average temperature of 89°, 

 i.e. 91 lb. of clean water w^as evaporated for every 

 100 lb. of steam from the slag." The amount of avail- 

 able steam from the slag was determined by con- 

 densing and measuring it. Seven experiments gave 

 as a mean 1017 lb. per ton of slag. Deducting 6-6 per 

 cent, for escape with the Incondensable gases, 950 lb. 



