i88 



NATURE 



[Decembei 



rainfall is 6-88 inches, in the Midland counties, which is 

 0-48 inch below the normal j whilst in the south-east of 

 England the aggregate fall is 10-47 inches, which is 

 i()8 inches more than the average. The absolutely largest 

 rain measurement is 13-78 inches, in the north of Scot- 

 land, which, however, is i-Sa inches less than the normal, 

 ihe number of rainy days are nowhere very different from 

 the average, the greatest number being fifty-eight days, in 

 the north of Scotland and in the south of Ireland ; th<? 

 least forty-seven days, in the south-east of England. The 

 duration of bright sunshine was in e.xcess of the average 

 over the entire kingdom, except in the English Channel. 

 The greatest duration is 382 hours, in the south-east of 

 England, which is sixty-nine hours more than usual. 



Mr. M. a. Hunter, of the electrical engineering depart- 

 ment of the Rensselaer Polytechnic, Troy, has succeeded in 

 producing metallic titanium in a state of purity greater 

 than has been hitherto possible. He uses the method of 

 Nilson and Petersson, i.e. reduces the tetrachloride of 

 titanium by heating it with metallic sodium in an air- 

 tight steel bomb capable of withstanding an internal 

 pressure of more than 5000 atmospheres. With a charge 

 of 500 grams of the tetrachloride and 245 grams of sodium, 

 after heating the bomb to redness to start the reaction and 

 then allowing it to cool, he obtained 71 grams of molten 

 metal, 31-5 of coarse and 4-5 of fine powder, as against a 

 theoretical yield of 126 grams. Analysis of the product 

 appears to indicate that the molten material is pure 

 titanium. Messrs. Hunter and Jones find that the density 

 of the metal is 4-50, and its sprcific boat between 0° C. 

 and 100° C. is 0-1462. 



Vol. iv. of the Journal of the Municipal School of 

 Technology, Manchester, a record of the investigations 

 carried out by the staff and students, and published in the 

 technical Press or the Proceedings of scientific societies 

 during the year 1910, is not so bulky as its immediate ! 

 predecessors, although it runs to 250 pages. The papers 

 reprinted are, on the whole, short, and they deal prin- 

 cipally with the applications of electricity in engineering or 

 of chemistry in textile processes. Of the longer papers, 

 those of Prof. Schwartz and his staff on the physical and 

 electrical properties of indiarubber and on the field of the 

 polyphase motor may be mentioned. In an important 

 paper by Prof. Haldane Gee and Mr. Harrison, reprinted 

 from the Transactions of the Faraday Society, the authors 

 bring forward weighty experimental evidence in favour of 

 the electrical theory of dyeing. .According to this theory, 

 a basic dye is positively, and an acid dye negatively, 

 charged, and the processes through which the fabric passes 

 before it is brought into the dye are such as to charge it 

 negatively or positively respectively, so that there may be 

 electrical attraction between dye and fabric. The number 

 of " laws of dyeing " which the electrical theory places on 

 a firm scientific basis is remarkable. 



.\mong primary plant materials, the pentosans, so widely 

 diffused, form a class of substances the origin and function 

 of which :u«' >iil! uncertain in spite of numerous researches 

 which have been made to throw light on these problems. 

 .An interesting contribution to the question is found in a 

 paper by Ciro Ravenna in the Gazzetia Chimica Italiana 

 (vol. xli., p. 115). It is shown as the result of a large 

 number of experiments, in which the pentosans were 

 estimated in the very young, primary leaves of the beech 

 and of Vicia faba minor, at dawn and sunset, that no 

 marked variation in their amount can be traced during the 

 period of chlorophyllian activity ; but at night consider- 

 able but irregular variations occur, generally in the direc- 



No. 2197. VOL. 88] 



tion of increase, but sometimei in that of <! 

 however, the stalk of the growing leaf is um: 

 nutritive solution containing 2 per cent, of d< 

 the plant allowed to continue its growth for v.wr 

 exposed to sunlight in an atmosphere free from 

 dioxide, the proportion of pentosans is very lar^;' 

 creased, being often nearly doubled. A similar, but 

 well marked, result was obtained in experiments in 

 the plant continued its growth in the nutritive solu^ 

 darkness, but in an atmosphere containing the ci 

 proportion of carbon dioxide. It is contended t) 

 pentosans are elaborated, not from the coi 

 saccharides, such as starch and cellulose, by • 

 changes, as is generally supposed, but that they are 

 direct from the simple carbohydrates. It is also 

 that when the chlorophyllian activity is inhibited,"! 

 pentosans diminish in relative amount, so that it 

 ap|)ear that, in addition to their other functions, theyl 

 capable also of acting as reserve material for the plant. 



A PROPOSAL for the reform of income tax and 

 duty is put forward by Mr. Douglas White in 

 Economic Journal, xxi. 83. According to the at 

 proposed system, the rate per pound at which an in 

 would be taxed would be proportional to the logarit 

 the income, so that as incomes increased in geometric 

 gression the rate of the tax would increase in arithr 

 progression. If, as Mr. White proposes, this system 

 carried out rigorousl>- with the use of logarithm tabli 

 would certainly, as alleged, remove the discontinuit 

 the present system, where what a man pays is re 

 largely by whether his income falls on a lucky n« 

 such as 499!., or an unlucky one such as 501 1. In 

 it would be sure to be simplified by retaining these] 

 continuities, for which a much simpler, obvious r« 

 is possible. 



A PAPER on the design of tall chimneys was 

 Mr. Henry Adams before the Society of Engine 

 December 4. Tall chimneys ought to be designed 

 scientific principles so that there is an absolute guar 

 for their stability. The object of Mr. .Adams's paper 

 to elucidate these principles and apply them to pra 

 There are several rules for determining the height 

 tall chimney ; in some towns 45 feet may be sufficient 

 in others 90 feet is the minimum allowed. The height] 

 be determined from the amount of coal burnt, or fr 

 length of boiler and flues. Four different rules were 

 for the sectional area, de[>ending upon the amount 

 burnt per hour, the fire-grate area, the horse-power 

 engine, or a combination of these with the height 

 chimney. The shape may be square, octagonal, or cir 

 the effective wind pressure varying in each case, 

 author's formula for wind pressure takes account of 

 and width, increasing with the distance from the 

 and increasint* also with reduced width. Eight aut 

 were quoted for the coefficient of pressure for a 

 shaft varying from 05 to 0-7854. The thickness; 

 brickwork varies 4^ inches every 20 feet in heij 

 the top length will be from one to one and a hal 

 thick, according to the height and diameter. The^ 

 width at base must be at least one-tenth, and if di 

 least one-twelfth, of the total height. .After the sectioB 

 drawn out to suit the conditions, the stability should 

 calculated at each set-off. The principles of stabi! 

 be illustrated by considering a solid square brick- ri 



Mr. Livingstone Sllmas, president of th- 

 of Mining and Metallurgy, delivered an address 

 annual prize distribution of the Sir John Cass T' 



