August 21, 1914. ___________________________________________________________________________________________________ 418 THE COLLIERY GUARDIAN. supply again the wire recovers its incandescence, but there is no flame. If, however, the supply be checked and restored suddenly, the gas ignites with an explo- sion; and the same thing occurs if a shock be produced in «the surrounding air (slamming a door, for instance), especially when the burner is not provided with a chimney. In the Welsbach burner, as in all others, there is a double current of air, the external air mixing with the gas issuing from the jet; but if the base of the lamp chimney be closed, the convergent combustion is rendered more stable, and the difficulty of igniting the gas to flame inside the chimney is increased. It should be noted that all the above-mentioned causes tend to lower the temperature of the incandescent spiral; conse- quently the intensity of the attraction between the gas mixture and the solid increases with the temperature. aIn fact, in the case of platinum it begins to be manifest below red heat (say, between 400 and 500 degs. C.), whilst for prepared copper it commences only at dull red heat. This phenomenon is a general one, and all filaments, when raised to incandescence by the electric current, acquire a sufficient temperature to set up rapid combustion in a mixture containing 9| per cent, of firedamp. Flame with a Metal Rod as Basis.—If the mantle of a Welsbach burner be replaced by a spiral or network of platinum (fig. 6), with an axially situated iron rod, and the platium be heated to incandescence, the surplus gas can be ignited at the tip of this rod, and will burn there with a tulip shaped, pale blue flame. If the rate of flow of the gas is checked, the flame will light back to the mouth of the burner, -showing that the velocity of flow of the gas was previously greater than the velocity of ignition. In short, the flame at the tip of the rod is the result of the unstable equilibrium estab- lished between the upward movement of the gas and the downward movement of ignition. 1. 2. 3. 4. Fig. 6. Application of Spectroscopic Analysis.—Spectro- scopic analysis can be applied to the detection of small quantities of hydrocarbons, and if a very small flame be used, the bands of the Swan spectrum can be easily detected in the dark. By giving a sufficient exposure, this spectrum can be made to yield a good photographic image, the flame of a spirit lamp in. high impress- ing a violet Lumi&re plate in less than two minutes. The sensitiveness of gelatino-bromide plates is not the same as that of the eye in the different regions of the spectrum, the yellow and orange bands not being repro- duced, the green band forming the limit recorded on the plate, though, on the other hand, the ultra-violet portion is doubled in width, and includes the A 388 p, p band, the Eder *>nd Valenta y band, and several others that are more refrangible but softer. The methane spectrum is almost identical with those of the hydrocarbons of petroleum spirit. It is examined by collecting the gas in a gasholder and burn- ing it in a mineralogical blowpipe flame, 3-4 mm. long, in front of the spectroscope slit. The spectral phenomenon does not depend on the relative propor- tions of hydrogen and carbon composing the various hydrocarbons, and must therefore be ascribed to the presence of the carbon. The presence of hydrocarbons, far too small in quan- tity to be detected by any other means, can be revealed in hydrogen by this spectroscopic analysis. For instance, hydrogen gas supposedly pure gave, with an exposure of 70 minutes, a spectrum exhibiting the violet band indicative of hydrocarbons. The impurity, which could not have exceeded one part in 100,000, was traced to the rubber tube employed for conducting the gas to the burner, this tube having previously served for coal gas. The operation is not difficult, the only precau- tions necessary being to adjust the hydrogen flame to a height of 3-4 mm., and to see that the supply of water to the gasholder is maintained throughout the exposure. If the flame goes out, the spectral image is not affected. ___________________________ The enquiry by Board of Trade Commissioners into the explosion at the Hunslet Steelworks last August, when nine men were killed and 18 seriously injured, has been concluded, and judgment delivered. The president (Mr. A. A. Hudson, K.C.) said there could be no doubt that the boiler was worked in a dangerous condition. The insurance company, according to their chief engineer, suggested that there had been some unprecedented and quite unexpected change in the quality of the Leeds water supplied to the boiler, causing an acceleration of scale, and an excessive density of water. After exhaustive enquiry it appeared to the Court that there had not been a particle of evidence to support the suggestion. The Court could not find the owners at fault. The Court thought that the actions of the insurance company must be the subiect of considerable adverse com- ment. The company’s policy was strongly against hydraulic tests, according to two of their officials, Mr. Ness and Mr Munroe. It was the opinion of the Court that if such tests had been applied in this case the explosion would never have occurred. The insurance company had allowed their inspectors to try to throw dust in the eyes of the Court as to the true cause of the explosion. No one in his senses, in the opinion of the Court, would issue a certificate that a boiler was safe for one month and no more. It would be suggested by the Court to the Board of Trade that their report should be sent to the Home Office in order that the inspectors under the Factories Acts should have their attention called to the non-compliance by the insurance company of the regulations governing examination. GERMANY’S MARKETS. 1.-SULPHATE OF AMMONIA AND BY-PRODUCTS OF COAL. One of the commodities in the manufacture of which Germany has held a leading place is sulphate of ammonia, and it is estimated that last year she made nearly 40 per cent, of the entire world’s output. The totals, as given by the Bochum Association, are as follow:— 1912. 1913. Tons. Tons. Germany 492,000 ...• 549,000 United Kingdom.. 379,000 ... 420,000 United States 151,000 ... 177,000 France 69,000 ... 75,400 Belgium 50,006 ... 48,600 Austria-Hungary 38,000 ... 45,000 Italy 15,000 ... 15,000 Spain ' 9,000 ... 15,000 Russia 2,600 ... 12,700 Holland 5,800 ... 5,000 Denmark 3,000 ... 3,000 The same association gives the following figures as representing the consumption of sulphate of anmonia in these years :— 1912. 1913. Tons. Tons. Germany 425,000 ... 460,000 North America 210,500 ... 235,000 Japan 87,000 ... 115,000 United Kingdom.. 90,000 ... 97,000 France 90,000 ... 90,000 Spain and Portugal ... 45,000 ... 57,000 Java 68,000 ... 57,000 Belgium 45,700 ... 42,000 Italy 33,000 ... 29,500 Austria-Hungary 13,000 ... 16,000 Holland 8,000 ... 8,000 2,000 Egypt 1,650 ... Sweden 1,300 ... 1,350 Denmark 230 ... 700 The consumption in Germany itself was no more than 275,000 tons in 1909. The German Syndicate in 1913 disposed of 335,232 tons, of which 62,456 tons were exported. In addition to the Westphalian production, the syndicate also dealt with the following quantities contributed by outside bodies, viz. :—Belgian Sulphate of Ammonia Comptoir, 8,145 tons; Upper Silesian Coke Works and Chemical Works Company, 2,508 tons; firm of Evence Coppee (Brussels), 299 tons. Germany in 1913 imported for home consumption 746,791 tons of nitrate of soda, of which, it is estimated, 497,860 tons were utilised for agricultural purposes. Reckoning an average content of nitrogen of 15 per cent, for nitrate and of 20’5 per cent, for sulphate, it may be assumed that 74,697 tons of nitrogen were consumed by German agriculture in the form of nitrates, and 94,300 tons in the form of sulphate. It was in 1911 that the latter ousted the former from first place. Considering the intimate relationship between the two industries from a competitive standpoint, the following comparison is of interest. It shows the agricultural consumption of these fertilisers in 1913 in the principal countries of the world :— Sulphate of ammonia. Nitrate of soda. c Tons. As nitrogen. Tons. Tons. As nitFg’n. Tons. Germany 460,000 ... 94,300 ... .497,860 ... 74,679 United Kingdom... 97,000 ... 19,885 ... 133,000 ... 19,950 France 90,000 ... 18,450 ... .355,000 ... 53,250 Spain and Portugal 57,000 ... 11,685 ... . 13,800 ... 2,070 Italy 29,500 ... 6,047 ... . 44,600 ... 6,690 Austria-Hungary .. 16,000 ... 3,280 ... . 7,150 ... 1,072 Belgium 42,000 ... 8,610 ... .308,200 ... 46,230 Holland 8,000 ... 1,640 ... .183,000 ... 27,450 Sweden 1,350 277 ... . 5,220 783 Denmark 700 134 ... . 4,900 735 Egypt 2,000 410 ... . 23,800 ... 3,570 North America ... 235,000 ... 48,175 ... 485,000 ... 72,750 Japan 115,000 ... 23,575 ... . 21,700 ... 3,255 Java 57,000 ... 11,685 ... , 15,000 ... 2,250 The total world’s production of sulphate of ammonia in 1913 amounted to 1,391,000, and that of nitrate of soda to 2,450,000 tons. It may be added that Germany is still an importer of sulphate; 34,629 tons were imported in 1913, and it was only in 1906 that exports began to exceed the imports. In 1913 348,808 tons were pro- duced in the Dortmund district, as well as 83,000 tons of benzol and 784,800 tons of tar. In the same year the synthetic production of sulphate passed from the theoretical to the practical stage, and recently the manufacture of artificial nitrate of chalk, potassium nitrate and nitrate of soda has greatly extended, as well as the production of sulphate by the electrolytic treat- ment of nitrate of chalk. It had been estimated that the output of artificial nitrates in 1914 would reach 220,000 tons. These and other causes have combined to retard the development of Germany’s export trade in sulphate; whereas, in 1910, no less than 93,000 tons were exported, the total fell to 74,445 tons in 1911, and 57,268 tons in 1912. More recently, however, strenuous efforts have been made to push the sale of German sulphate on the Continent, and notably in the Southern ports of North America and Java. Of the total exports from Germany in 1912, 19,723 tons were sent to Belgium, 18,122 tons to Holland, 5,621 tons to the Dutch Indies, 4,313 tons to France, and 3,816 tons to Italy. The last-named country, it may be observed, draws large supplies from Austria-Hungary. Under this heading some particulars may be added with regard to Germany’s export trade in coal by- products generally. The accompanying table shows exports in 1895, 1905, 1911, and 1912, the last year for which full details are available :— 1895. 1905. 1911. 1912. Tons. Tons. Tons. Tons. Sulphate of ammonia 1,336... 27,589.. . 74,445.. . 57,268 Tar 16,048... 42,889.. . 53,452.. . 76,584 Pitch Benzol, cumol, toluol, and 8,937... 4,119.. .109,718.. . 78,277 other light tar oils Oils of anthracene, carbol, 1,966... 6,560.. . 26,866.. . 32,481 creosote, and other heavy tar oils, including asphalt-naphtha 3,619...23,292.. .105,037.. .130,482 Naphthalene 300... 2,735.. . 9,333.. . 6,749 Anthracene Phenol (carbolic acid, 1... 13.. . 65.. 596 phenyl-alcohol) 776... 5,275.. . 3,175.. . 3,571 Cresol 476.. 594 Oils and salts of aniline... Naphthol and naphthy- 7,135...19,421.. . 7,485.; . 7,559 lamine . Anthraquinone, nitro- — ... — .. . 2,750.. . 2,672 benzol, and other tar derivatives — ... — .. . _ 4,876.. . 5,346 In 1912 Germany’s largest market for coal tar was Russia (19,898 tons). Of the total exports of pitch, 17,449 tons went to Belgium, and 44,325 tons to France. Nearly the whole of the light oils exported went to France, whilst 14,285 tons of heavy tar oils were sent to the same country, 73,940 tons to Holland, and 16,792 tons to the United States. The last-named country was also the chief customer for phenol (1,078 tons), and aniline oils and salts (2,335 tons). The tendency in Germany, however, has been to devote increasing attention to finished products, and this resume would not be complete without some refer- ence do the external trade in coal tar dyes. In 1912 Germany exported 59,696 tons of coal tar dyes and 11,589 tons of alizarine and similar manufactures. The chief markets for the former were as follows :—United States, 14,639 tons; Great Britain, 11,062 tons; Austria- Hungary, 5,786 tons; Italy, 3,899 tons; China, 3,739 tons; Japan, 3,720 tons; British India, 3,559 tons; Belgium, 2,163 tons; Russia, 1,266 tons; France, 1,230 tons; Holland, 1,383 tons; Sweden, 947 tons; Switzer- land, 754 tons; Spain, 734 tons; Brazil, 692 tons; Portugal, 430 tons; Mexico, 423 tons; Canada, 417 tons; Turkey, 407 tons; and Denmark, 224 tons. In regard to alizarine products, 3,154 tons went to British India; 2,973 tons to the U.S.A.; and 2,514 tons to Great Britain. It will be noted that, for most of the commodities referred to above, Great Britain has been one of Ger- many’s best customers. It will now be necessary to repair deficiencies that must resiflt from the war; pos- sibly new plant will have to be installed, and new methods adopted; but with all the facilities in our possession, it would appear to be possible at the same time to make serious inroads upon an important section of Germany’s foreign trade. ____________________________ Grimsby Coal Exports.—The quantity of coal exported from Grimsby during the week ended Friday, 14th inst., was as follows :—Foreign : To Arendal, 670 tons. Coast- wise : To London, 899 tons; Whitstable, 280; and Yar- mouth, 194. Totals: Foreign, 670; and coastwise, 1.273 tons, compared with 23,182 and 511 tons respectively for the corresponding week last year. Coal Trade of Alexandria.—The following table extracted from the report of Mr. Vice-Consul Geary shows the quan- tity of coal imported into Alexandria from each of the principal supplying countries during the years 1912-13, and the yearly average for the period 1906-12 and the compara- tive increase or decrease in 1913 :— Yearly Country. 1912. 1913. average, 1906-12. Tons. Tons. Tons. United Kingdom ........... 1,174,387... 1,222,082... 1,200,875 Belgium .................... 4,149... 1,539... 2,041 France and Algeria ........ 25... 33... 378 Germany .................... 49,168.. 40,251... 25,827 United States............... 83,363... 12^,955... — Total (including others') 1,311,092... 1,399,860... 1,065,987 There was a great variation both in prices and freights during 1913. In 1912—the year of the great British coal strike—freights ranged from 10s. 6d. to 13s. 6d., while prices varied from 2-1 5s. to £2 18s. The following shows the average prices and freights during 1913 :— Price (Free into Wagons). Cardiff. Newcastle. £ s. d. <£ s. d. £ s. d. £ s. d. January ..... 1 13 6 to 1 14 0 ... 1 8 6 to 1 9 0 February .... 1 It 6 „ 1 15 0 ... 1 8 6 „ 1 9 0 March ...... 1 14 6 „ 1 15 0 ... 1 8 0 „ 1 8 6 April........ 1 14 0 „ 1 14 6 . .. 1 7 0 „ 1 7 6 May ........ 1 13 6 „ 1 14 0 ... 1 7 0 „ 1 7 6 June ........ 1 13 o „ I 13 6 ... 1 6 6 „ 1 7 0 July ........ 1 12 0 „ 1 12 6 ... 1 6 0 „ 1 6 6 August ...... 1 H 6 „ 1 12 0 ... 1 6 0 „ 1 6 6 September ... 1 9 3,,1 9 9 ... 1 6 0,, 1 6 6 October...... 1 9 0 „ 1 9 6 ... 1 5 6 „ 1 6 0 November ... 1 9 0 ,, 1 9 6... 1 5 0,, 1 5 6 December ... 1 8 6 ,, I 9 0 ... 1 5 0,, 1 5 6 Freights. Cardiff. Newcastle, s. d s. d*. s. d. s. d. January ........... — 11 6 ... — 11 6 February .......... — 12 6 ... — 12 6 March ............. 10 9 to 11 3 ... 10 9 to 11 3 April............... 10 0 „ 10 3 ... — 9 9 ...... May ............... 10 3 „ 10 6 ... 10 3 to 10 6 June ............... — 11 0 ... — 11 0 July ............... — 9 3... — 9 3 August ............. 8 9 to 9 3 ... 8 9 to 9 3 September .......... — 9 3... — 9 3 October ........... 9 3 to 9 9 ... 9 3 to 9 9 November .......... 8 9„ 9 3... 8 9 „ 9 3 December........... 8 9 ,, 9 3 ... 8 9 ,, 9 3