April i, 1909] 



NA TURE 



'00 



be available on which to trace changes. The present 

 distribution of contributing stations, India, western 

 Europe, and America, fulfils in some sort this need, 

 though a distinct lacuna exists in the longitude of 

 Australia. 



.■X paper, by Prof. Hale, on the measurement of 

 spectroheliograms gave rise to an interesting dis- 

 cussion concerning the methods of reducing the 

 photographs already obtained. In his case, after 

 some e.xperiments, a photometric method of determin- 

 ing the areas of selected fiocculi had given satis- 

 factory accord, while Sir Norman Lockyer was able 

 to report that, in the direct measurement of the series 

 of spectroheliograms being formed at South Kensing- 

 ton, and in spite of the difficulties, good agreement 

 was obtained by the two observers engaged in the 

 work. In the study of the relation between solar 

 activities and terrestrial changes, measurements of the 

 numbers and areas of fiocculi are likely to be of 

 great importance. .\t all times the areas affected are 

 greatly in excess of the spotted areas, while during 

 the almost spotless periods of sun-spot minima, 

 fiocculi persist (in lessened degree), and bridge what 

 would be otherwise practically a gap in the records. 



The computing bureau of the union, established 

 at Oxford under Prof. Turner, will make special 

 studies of such spectroheliograph negatives as are 

 entrusted to it by members : this, however, without 

 prejudice to the right of reducing and studying photo- 

 graphs by those responsible for their taking. A start 

 has alreadv been made at Oxford on some plates lent 

 by Prof. Hale. 



The difficulties in the selection of the fiocculi, re- 

 corded on the plates, for measurement, together with 

 differences in size and quality of the photographs, 

 make satisfactory and comparable measures far from 

 easy. Great credit is due to the institutions and 

 workers on this subject for the progress already 

 made. 



A proposition by Sir Norman Lockyer supporting 

 the project for the establishment of a solar physics 

 observatory in Australia was carried unanimously. 

 This project, if carried into effect, would add another 

 link to the chain of spectroheliographs girdling the 

 earth. 



An account, by M. Deslandres, of the spectro- 

 heliograph equipment and work accomplished with 

 it at Meudon, together with an excellent picture of 

 the sun in K„ light, and a series of spectra in the 

 neighbourhood of K used for the determination of 

 the radial velocities involved in the solar activities, 

 concludes the volume. 



The delegates were invited by Prof. Hale to come to 

 California for the next meeting, so that the date 1910 

 and the place Mount Wilson were provisionally de- 

 cided upon, Prof. Hale being thanked for his kind 

 invitation. 



The publishers are to be congratulated on the get- 

 up of the book, the paper and printing being good 

 and the binding neat and effective. 



T. F. C. 



THE MANUFACTURE OF BASIC STEEL. 



OF the many varieties of cast- or pig-iron, the 

 three following percentage compositions may be 

 taken as representing three most important tvpes : — 



(") W ' (< ) 



Carbon 3-5 ... 35 ... 35 



Silicon ... ... 25 ... 10 ... 2"5 



Manganese ... o'5 ... 2'o ... 0'6 



Sulphur... ... 0'05 ... o'o6 ... 0^04 



Phosphorus ... 0'05 ... 2'0 ... i"6 



An average chemical specification with regard to 

 sulphur and phosphorus in steel is " not to exceed 

 NO. 2057, yOL. 80] 



006 per cent, of each." For certain Government 

 work the standard is 004, and easier specifications 

 allow of o'o8, but o'o6 is a fair average. 



The first pig (a) is suitable for conversion into steel 

 by the acid process, in which the oxidising agent, 

 whether oxygen of the air or oxygen from oxide 

 of iron, acts upon the metal while it is con- 

 tained in a vessel or a hearth composed mainly 

 of the acid material silica. In this process 

 the slag is necessarily of an acid nature, and 

 sulphur and phosphorus therefore are not eliminated. 

 Enormous quantities of iron ore are available, which 

 contain very much higher proportions of phosphate 

 than the haematite from which the cast iron of the (a) 

 variety is produced, and as in the blast furnace 

 practically all the phosphorus in the charge of ore, 

 fuel, and flux enters into the metal, pig-irons are 

 made that are much too high in phosphorus for 

 conversion into steel by the acid process. By using 

 a vessel or a hearth lined with basic material, such 

 as burnt dolomite or magnesia, the steel can be 

 finished in contact with a slag sufficiently basic to 

 effect the removal of the phosphorus. The basic 

 process as commonly worked some years ago, and 

 sometimes even to-da}', consisted in charging a 

 mixture of about equal parts of pig-iron and scrap on 

 a basic hearth, and then, by additions of iron ore 

 and lime, eliminating the silicon and manganese, as 

 well as the carbon and the phosphorus, to the extent 

 necessary in the manufacture of mild steel. By this 

 ordinary method of working, as the phosphorus is 

 only sufficiently eliminated when the carbon is low, 

 the process was generally used for the manufacture 

 of mild steels, as unless the highly phosphoric slag 

 is removed from the surface of the metal at the end, 

 during re-carburisation phosphorus is reduced from 

 the slag, resulting in an increased percentage of 

 phosphorus in the bath. .Sulphur is not to any great 

 extent removed during the process as ordinarily con- 

 ducted, and although the amount of sulphur in the 

 bath can be reduced by additions of fluor-spar during 

 the conduct of the process, these additions, if in excess, 

 not only prove destructive to the banks of the basin- 

 shaped receptacle, but render the phosphate in the 

 slag insoluble, and thus decrease its value for agri- 

 cultural purposes. 



The pig-iron for the basic process must therefore 

 be comparatively low in sulphur for successful regular 

 working, and if bv any means it should be high in 

 sulphur must be subjected to a desulphurising 

 process, such as the Massenez manganese process or 

 the Saniter o.xychloride or fluoride process. 



The ordinary conditions for the manufacture in the 

 blast furnace of pig-iron high in silicon content are 

 those favourable to the production of a pig-iron low- 

 in sulphur, but a high-silicon pig-iron used in the 

 ordinary basic process is again destructive to the banks 

 of the furnace. The manufacture of a low-silicon 

 low-sulphur pig, such as (6), can be effected by the 

 use of manganiferous ores added to the blast-furnace 

 charge. These ores are expensive, and the manganese 

 in the pig-iron is lost during the conversion of the 

 pig into steel. These statements give shortly the 

 conditions connected with the manufacture of basic 

 steel. 



Many attempts have been made to improve the 

 ordinary method of working, either from the point 

 of view of being able to accept pig-iron high in 

 sulphur, or, on the other hand, of being able to use a 

 pig-iron high in silicon, because of the difficulty and 

 expense connected with making the pig low in silicon 

 and sulphur. 



In 1894 a patent was granted to Messrs. Bertrand 

 and Thiel for removing the silicon, the bulk of the 

 phosphorus, and part of the carbon and manganese in 



