4 2 



NA TURE 



[May 8, 1884 



southern spot was the brighter of the two, and " appeared then 

 to be composed of a multitude of bright peaks, forming on its 

 northern border a row of brilliant, star-like dots of light." The 

 white spots disappeared after the inferior conjunction, which 

 occurred on February 21. 



At the sitting of the Academy of Sciences of Paris on March 

 24, M. Trouvelot mentioned that on two hundred and forty-two 

 occasions since February 187S he had observed one or other of 

 the luminous spots, and occasionally both, and had made up- 

 wards of one hundred and twenty drawings. Since April 5 in 

 the present year he had not lost sight of the northern spot, which 

 alone was visible at that date. He did not find the spots affected 

 by the diurnal rotation of the planet, and hence infers that the 

 axis passes either through or very close to their centre. In this 

 view it will be interesting to compare the position of the axis of 

 the spots determined by his observations with the results ob- 

 tained by De Vico and others. An attempt in this direction, 

 founded upon some of the more satisfactory drawings, did not 

 promise a near agreement. M. Trouvelot adds that the spots 

 appear almost permanent, and thinks they are the summits of 

 high mountains projecting beyond the cloudy envelope, generally 

 opaque, which covers the planet. 



The observations in 1S77-78 were made at Cambridge, U.S., 

 those of the present year at the Observatory of Meudon. De 

 Vico's investigation on the position of the axis of Venus ap- 

 peared in the Memoirs of the Observatory of the Collegio 

 Romano for 1840-1841 : it can hardly be said that his results, 

 founded upon data necessarily vague, have inspired much con- 

 fidence amongst astronomers. He made the inclination of the 

 equator of Venus to the ecliptic 53 11', and the longitude of the 

 ascending node 57 19' for 1841 ; the rotation of Venus in side- 

 real time, 23I1. 2im. 21 '93s. : these are the figures quoted in 

 Secchi's " Life of De Vico." 



The Great Comet of 1S82. — Prof. Howe notifies that he 

 has undertaken a definite determination of the orbit of this comet, 

 which will doubtless be a work of some labour. Thus far calcu- 

 lation appears to indicate that the comet was moving in an ellipse, 

 with a period not differing much from eight centuries : Kreutz 

 gave 843, Fabritius 823, Frisby 794, and Morrison 712 years; 

 the orbit of Fabritius depends upon the widest extent of observa- 

 tion. Between the earliest and latest accurate positions the 

 comet described an orbital arc of 340 : a similar arc was traversed 

 by the comet of 1680 between iis discovery by Kirch on the 

 morning of November 14 and the last observation by Sir Isaac 

 Newton on March 19 following. 



Those who may have unpublished observations of position of 

 the great comet of 1SS2 will do well to communicate them to 

 Prof. Howe forthwith. 



Brorsen's Comet of Short Period. — We have not yet 

 met with any intimation that an ephemeris of this comet for the 

 approaching reappearance is being prepared : that for the last 

 return in 1879 was furnished by Prof. L. R. Schulze of Dobeln ; 

 the time of perihelion passage was about eleven hours later than 

 his calculation gave it. Disregarding perturbation, the comet 

 would be again due at perihelion in the middle of September 

 next, in which case it would be observable in the two hours 

 before sunrise, in August and September, under somewhat 

 similar conditions to those in 1S73. Supposing the perihelion 

 passage to occur September 14-5, the comet's position at that 

 time would be in about R.A. I54°'5 and N.P.D. 76°'2, the 

 distance from the earth I '41. 



Since the discovery of this comet within one day of perihelion 

 passage in 1S46 it has been observed at four returns, viz. in 1S57, 

 186S, 1873, and 1879. 



THE IRON AND STEEL INSTITUTE 



'"THE annual meeting of the Iron and Steel Institute took place 

 ^ at the Institution of Civil Engineers on April 30 and May 

 I and 2. The proceedings commenced with the reading of the 

 Council's Report and the Accountant's statement, and with the 

 presentation of the Bessemer Medal jointly to Mr. E. II. Martin 

 of Dowlais and Mr. E. Windsor Richards of Middlesbrough, in 

 recognition of the part taken by them in introducing the basic 

 process for the manufacture of steel. In returning thanks, Mr. 

 E. Windsor Richards mentioned that his firm, that of Messrs. 

 Bolckow, Vaughan, and Co., were now making no less than 

 3000 tons per week by this process from Cleveland pig-iron, such 



as would have been thought, until recently, wholly unsuitable 

 for steel-making. Sir H. Bessemer, who was present, con- 

 gratulated the recipients and the steel trade generally upon the 

 brilliant success of Messrs. Thomas and Gilchrist's invention. 



The first paper read was by Mr. I. L. Bell, F.R.S., and dealt 

 with the use of Raw Coal in the Blast Furnace. It pointed out 

 that this question, as being more complicated than that of coke, 

 had never been treated before the Institute, although raw coal 

 was largely used in the United States in the form of anthracite, 

 .uid in Scotland in the form of the splint coal of the Lanarkshire 

 coal-field. It is with the latter that the paper was chiefly con- 

 cerned. Taking the Brockwell seam as a good specimen of 

 Durham coking coal, analyses were given of it first in its raw 

 state, and secondly when converted into coke, together with the 

 number of heat units developed from one weight-unit of each. 

 It appears that this number is 7437 in the case of the coal, and 7395 

 in the case of the coke, so that the heat developed in the two 

 kinds of fuel is practically the same. This theoretical result 

 wns checked by experiments on a large scale made upon the 

 North-Eastern Railway, using the same engines and the same 

 weight of trains. The trials were continued for one week with 

 each kind of fuel, full loads being taken to the place of ship- 

 ment and the waggons returned empty to the collieries. The 

 result in one trial in pounds consumed per train mile was 40-5 

 of coal and 41 '6 of coke. In another experiment the difference 

 was larger, but still it was not serious, and the theoretical deduc- 

 tion just given is thus fully confirmed. This equality of value 

 between coal and coke is not, however, found to exist in the 

 blast furnace, for the simple reason that the volatile constituents 

 of the coal are scarcely oxidised at all, and therefore give but 

 very little useful effect. They might, however, be utilised in 

 another way, namely, as a means of reducing the oxide of iron 

 to the metallic state. The gas from the coal would thus do part 

 of the work now done by CO, and might enable a larger quan- 

 tity of CO., to be evolved in the escaping gases. At present, 

 however, this effect does not seem to be realised in practice. 

 Analyses were given of the Lanarkshire splint coal, which 

 show' that, as a source of heat, it is inferior by about 30 per 

 cent, to the South Durham coal. Analyses were also given of 

 the escaping gases where this coal is used for smelting, and from 

 this the quantity of heat evolved and appropriated was calculated, 

 and compared with furnaces using coke. It thus appears that 

 the raw coal occasions a much less perfect oxidation of the carbon, 

 and in consequence a much smaller evolution of heat. On the 

 other hand, the hydrogen contained in the coal affords a large 

 supply of heat, but this and far more is absorbed in the expulsion 

 of the volatile constituents, which is sufficiently proved by the 

 very low temperature of the escaping gases, 190° C. as compared 

 with 332° C. in the case of coke. 



As regards the proportion of C0 2 and CO in the escaping 

 gases, it appears that with coal it is much below the limit which 

 Mr. Bell has fixed as the maximum compatible with reduction, 

 viz. I of CO., to 2 of CO. Hence it follows that a considerable 

 quantity of CO., must have diss, Jvei 1 carbi in and so returned to CO. 

 Calculating : .this quantity, it appears that the total carbon which 

 readies the hearth and gives up its heat for the fusion of iron, 

 &c, is not very different in the two cases. Why then is there 

 so large a disappearance of CO„ in the Scotch furnace as com- 

 pared with the English? Mr. Bell attributes it to the fact that 

 the latter is So feet high, whilst the former, though 74 feet high, 

 was only filled to 85 per cent, of its real capacity. The effect of 

 the lower furnace is to diminish the time during which the ore 

 is exposed to the reducing agency of CO, whilst still too cool 

 for the fuel to decompose CO,,. In addition it is suggested that 

 the presence of hydrogen in the coal might cause the formation 

 of steam, which would subsequently react on the fuel and tend 

 to lower the percentage of COj. On the whole it appears that 

 when using raw coal in the blast furnace there is a waste of 

 carbon to the extent of 372 units ; but before recommending 

 that the coal should be coked in order to avoid this loss, the 

 commercial aspect of the question must be considered, and it 

 appears that the cost of coking even where possible would in 

 many cases exceed the saving attained. A further point, however, 

 which needs consideration is the possibility of condensing the 

 tar and ammonia given off by the coal and so saving the valuable 

 products. Here we have a difficulty in the Scotch furnaces from 

 the enormous quantity of gas which would have to be dealt with ; 

 nevertheless the results attained by Messrs. Baird in the Gartsherrie 

 furnaces (given below).seem to show that the yield of ammonia is 

 about the same as in the Simon-Carves process for coking, as used 



