August i8, 1923] 



NA TURE 



149 



an entire absence of rain. The observations are 

 discussed for the period of twenty-two years, from 

 1900 to 1921. Atmospheric pressure varies very 

 regularly throughout the year ; a minimum is reached 

 about the beginning of May, and a second minimum 

 occurs about the beginning of October. The diurnal 

 range of the barometer is very regular and does not 

 vary much in the course of the year. The coldest 

 month is January, with a mean temperature of 

 22°-5 C. ; the warmest month is June, with a mean 

 temperature of 34°- 1 C. The short rainy season 

 causes a second minimum, 3i°-2 C. in August. The 

 second maximum temperature occurs about the end 

 of September, approximately, the same time as the 

 second minimum of pressure. Diurnal range of 

 temperature is greatest, i4°-5 C, in April, and least, 

 io°-i C, in September. Statistical values are also 

 given of humidity, vapour pressure, cloud, sunshine, 

 wind, and the upper winds. The amount of' rainfall 

 is small, averaging only 148 mm., or rather less than 

 6 in. for the year ; nearly 90 per cent, of this falls 

 in July, August, and September. The discussion 

 will serve as a specimen for other stations. 



GOLDFIELDS OF WESTERN AUSTRALIA. The 



Department of Mines of Western Australia has 

 issued an important description of the gold deposits 

 of Western Australia, written by Mr. A. Gibb Mait- 

 land. The author classifies the gold-bearing deposits 

 under the following five heads : i . Simple or fissure 

 veins, carrying auriferous quartz with or without 

 accessory minerals. 2. Composite veins or lodes, 

 which are made up of a number of more or less 

 parallel lenticular veins. 3. Sheeted zones, consist- 

 ing of a series of closely spaced and parallel veins, 

 generally of small dimensions. 4. Stockworks, which 

 are irregular networks of small auriferous quartz 

 veins. 5. Shear zones or bands of schistose rocks, 

 impregnated with various sulphides, iron pyrites 

 often predominating, and containing little or no 

 quartz. In addition to the above classification, the 

 author, when discussing the individual goldfields, also 

 mentions the so-called " lode formations," which he 

 defines as " impregnations of zones of previously 

 existing rocks and confined largely to shear zones, 

 characterised by much crushing and fracturing as 

 well as the deposition of quartz along such 

 fractures." It would appear that such lode forma- 

 tions are especially important in the Boulder and 

 Kalgoorlie districts of the East Coolgardie gold-field, 

 which is itself by far the most important of the 

 Western Australian gold-fields, having produced over 

 17 million ounces of gold out of a total of 31 million 

 ounces produced by Western Australia, whilst no 

 other individual goldfield has produced above 3 

 million ounces. The gold production of Western 

 Australia reached a maximum in the year 1903, 

 when the output was just above 2 million ounces ; 

 since that time it has been gradually declining, until 

 in 1918 it was only 876,511 ounces, but the account 

 here published shows that there is good reason to 

 hope that the present output may be reasonably 

 expected to be maintained for a considerable time 

 to come. 



The Earth's Magnetic Field. — In the issue of 

 Terrestrial Magnetism and Atmospheric Electricity for 

 March-June, Dr. L. A. Bauer gives the chief results of 

 a preliminary analysis of the earth's magnetic field 

 for 1922 based on the British Admiralty magnetic 

 charts for 1922 and those of the United States 

 Hydrographic Office for 1920 corrected to 1922. He 

 finds that the field at any instant is compounded of 

 an internal field having a potential and representing 

 about 94 per cent, of the total, an external field also 



NO. 2807, VOL. 112] 



having a potential and a non-potential field of about 

 equal strengths. The time change of the field is 

 equally complex. On the whole, dviring the past 

 80 years the north end of the axis of the internal 

 field has moved slowly towards the west and south, 

 and the intensity of magnetisation has decreased at 

 the rate of 1/1500 of itself per annum. The intensity 

 over land areas is greater than over ocean areas in 

 the same latitude, and the decrease during the past 

 37 years greater over ocean parallels than over land 

 parallels of latitude. 



Production of Smokeless Fuel. — A pamphlet 

 entitled " The Story of the Scott-Moncrieft" Retort 

 for producing Smokeless Fuel," printed by Moultons 

 (Printers) Ltd., Brighton, contains material of some 

 historical interest in connection with the efforts which 

 have been and are being made to solve the problem 

 of the low-temperature carbonisation of bituminous 

 coal for the production of smokeless fuel. It deals 

 with the recent and pioneering efforts (dating back 

 to 1870) of Mr. W. D. Scott-Moncrieff. Since 1921 

 he has been engaged in experiments made at the 

 Newhaven Gas Works in order to perfect a r-etort 

 for which " final success " is claimed. In an enclosed 

 analytical report are given tables of results of 

 carbonisation trials which seem typical of those to 

 be expected from the carbonisation of Durham and 

 Yorkshire coals at temperatures about 600° C. The 

 fuel produced is stated to be " smokeless and suitable 

 for transit," and the " results exceed all expectations." 

 Insufficient evidence is adduced to enable the reader 

 to judge the validity of these claims. One can only 

 await with interest the appearance of further details, 

 with the hope that, if a solution has been found of a 

 problem which has proved so baffling, both on the 

 technical and the economic sides, credit will fall to 

 one of the pioneering workers. 



Oxidation of Carbon. — The well-known method 

 of oxidation of organic substances by a mixture of 

 chromic and sulphuric acids has been recently re- 

 examined by J. L. Simon, and the results, some of 

 which were unexpected, have been communicated in 

 a series of notes to the Comptes rendus of the Paris 

 Academy of Sciences. With the usual mixture of 

 potassium bichromate and sulphuric acid some com- 

 pounds are completely, others only partiallv, oxidised. 

 The substitution of silver bichromate for potassium 

 bichromate in the mixture was found to give complete 

 combustion in some cases where the classical mixture 

 gave only partial oxidation. Interesting and un- 

 expected results were obtained on applying these two 

 mixtures to the oxidation of the various forms of 

 carbon. Pure graphite, using the silver oxidising 

 mixture, was completely oxidised to carbon dioxide 

 (with a trace of carbon monoxide) in half an hour at 

 100° C. : in the absence of silver the combustion was 

 partial, from 66 per cent, to 72 per cent, being burnt. 

 In a later communication (July 23) it is shown that 

 the deficit in the absence of silver is related to the 

 constitution of the compound, and the aromatic 

 compounds can be clearly distinguished from others 

 by the different figures given by tlie two reagents. As 

 regards the different forms of carbon : in the presence 

 of silver, graphite is completely burnt, diamond is 

 not oxidised at all, while for various forms of charcoal, 

 coke, and coal, only from i per cent, to 6 per cent, 

 is burnt. The fact that it is possible to oxidise 

 graphite by thirds is in agreement with the view of 

 a hexagonal distribution of the carbon atoms, and 

 there is a marked experimental difference between 

 graphite and certain varieties of black carbon which 

 it is natural to attribute to a difference in consti- 

 tution. 



