64 



NATURE 



[November 15, 1900 



In several parts of Germany considerable attention is being 

 paid to electrical appliances that can be used on the farm. Mr. 

 Hughes, U.S. Consul at Coburg, reports that near Ochsenfurt, in 

 Bavaria, a company, composed of land-owners and small 

 farmers, has been organised for the establishment of an 

 electrical system for use on their farms and in villages. The 

 powder is to be generated by steam and water, and the current 

 to be distributed from a central station to the places at which it 

 is wanted. Sub-stations are to be established at given points, 

 with the necessary apparatus for connecting with the farm or 

 other machinery, and also for lighting purposes in the houses, 

 offices, roads, and village streets. 



From the U.S. Experiment Station Record (yo\. xii., No. i), 

 we learn that an interesting step, looking to the advancement of 

 agriculture in the Russian Empire, has recently been taken, on 

 the recommendation of the Ministry of Agriculture and Imperial 

 Estates, in the inauguration of a system of commissioners of 

 agriculture to preside over the agricultural affairs in their 

 respective provinces or governments, and to seek to prom ote 

 and improve the agricultural conditions in general. Provision 

 has been made for such commissioners in twenty differe nt 

 governments of the Empire, and the funds for their maintenance 

 became available with the beginning of the present year. These 

 commissioners will have charge of all public measures relating 

 to agriculture and rural affairs, and will exercise supervision 

 over all local agricultural institutions maintained by the govern- 

 ment. They will inquire into the agricultural needs of their 

 respective governments, and will r ecommend government aid 

 for such local or private enterprises as merit special encourage- 

 ment. Connected with the commissioners' offices will be corps of 

 agricultural specialists and instructors, who will be assigned to 

 the work by the Ministry of Agriculture and Imperial Estates. 

 They will go out among the landowners and peasants for the 

 purpose of collecting data regarding the actual conditions of 

 various branches of agriculture, to diffuse general information on 

 agricultural topics, and endeavour co improve the methods and 

 practices in vogue. The inauguration of this system would seem 

 to be a distinct mark of progress. Taken in connection with 

 the recent decrees regarding the establishment of additional 

 agricultural experiment stations and systems of agricultural 

 education, already referred to, it should materially improve 

 and modernise the practice of agriculture in Russia. 



A SIMPLE method of recording the speed of motor cars and 

 other vehicles has been devised by M. L. Gaumont, and accounts 

 of the device appear in Cosmos and La Nature of November 3. 

 The instrument consists simply of a camera with a double 

 shutter, by which two exposures are made of the same plate, 

 separated by a known interval of time. On developing the 

 photograph two images are obtained of the moving object, and, 

 by measuring the distance between them, the dimensions of the 

 car being supposed known and also measured on the plate, it is 

 easy to calculate the speed of the car at the instant when the 

 photograph was taken. The object is to assist the authorities in 

 regulating the speed of these vehicles and checking furious 

 driving. 



The Cancer Society has just issued its annnal report, from 

 which we learn that one of the great aims of the Society has been 

 to direct public attention to the insidious danger threatening in 

 the increase of cancer. During the past year the Committee 

 have sent out Dr. Arthur C. Duffey to the United States to report 

 on the equipment of the newly-erected Cancer Laboratory at 

 Buffalo, and on his return a detailed report was issued to all 

 the medical schools and to the Press. A prize of fifteen 

 guineas, offered by Miss Scott for the best original essay on the 

 pi-esent state of cancer science, has been awarded to Dr. 

 Alexander Eraser, of Manchester. An elementary pamphlet by 



NO. 1620, VOL. 63] 



Dr. Herbert Snow, laying down maxims for the avoidance and 

 early recognition of cancer, has been issued, together with 

 numerous other publications bearing on the subject. ' ' 



Dr. Quiring Majorana contributes to the Atti dei Lincei an 

 account of experiments dealing with the behaviour of carbon at 

 high temperatures and pressures. In M. Moissan's experiments 

 on the transformation of diamonds, the partial crystallisation of 

 the carbon was attributed to (i) the high temperature of the 

 central mass, (2) the solubility of the carbon in the metallic 

 mass, and (3) the pressure. Dr. Majorana, finding that in his^ 

 previous experiments the crystals obtained were much smaller 

 than those produced by Moissan, has conducted a fresh series of 

 experiments in which he has maintained the carbon at a pressure 

 exceeding, and a temperature equalling, that employed by 

 Moissan, for a considerably longer period of time, without pro- 

 ducing so marked an increase of density. From this he 

 considers it probable that the solubility of the carbon in the 

 surrounding medium is one of the principal factors in the 

 crystallisation. 



A series of papers dealing with the properties of pozzolana, 

 and its use in mortars and cements exposed to the action of sea- 

 water, is contributed to the Gazzetta chimica italiana by M. O. 

 Rebuffat. In one of these papers the author discusses the 

 reactions of the several silicates of alumina entering into the 

 composition of pozzolana, with especial reference to the produc- 

 tion of artificial cements of this character. In connection with 

 the action of sea-water, the principal results are that sea-water 

 transforms the cement of mortars containing pozzolana into a 

 hydrated silicate of alumina containing small quantities of lime 

 and {magnesia and quantities not negligible of alkalis. The 

 silicate, by its composition, is altogether unaffected by the salts 

 of sea-water. Seeing that in mortars immersed in sea-water the 

 lime, after binding the mortar together, ultimately disappears 

 completely, the use of mixtures of cement and pozzolana is not 

 recommended. The author advocates the old plan of screening 

 the pozzolana, and deprecates the use of finely ground pozzolana 

 mixed with sand. 



Prof. R. Sissingh, o» Amsterdam, has published a short 

 treatise on the general properties of images formed by direct 

 pencils traversing a system of spherical surfaces. This treatise 

 contains a simplification of the proofs applicable to an optic system 

 formed of lenses centred on the same axis. The theory now 

 offered is essentially physical in character ; at the same time,, 

 the ordinary geometrical properties of images are also estab- 

 lished, and the optical properties of the eye are considered. 

 Prof Sissingh takes no account of aberration other than 

 chromatic aberration. The monograph is reprinted from the 

 Verhandelingen of the Royal Academy of Amsterdam, and 

 published by Johannes Miiller, of Amsterdam. 



We have received from Sir Charles Todd, Government 

 Astronomer of South Australia, a report upon the Rainfall of the 

 Colony during 1897, showing the monthly and yearly values at 

 415 stations, together with the number of days on which rain 

 fell, the greatest fall in one day, and the mean of the rainfall for 

 a number of previous years. The rains during the year were 

 irregular and, on the whole, below the average over the whole 

 Colony ; in October a dry spell set in, which lasted during the 

 rest of the year, and practically ruined the agricultural prospects. 

 As an instance of the lengthy drought to which places in the 

 interior are subject, Charlotte Waters in 1896 had 2-84 inches 

 only, and i •16 inches in 1897. A valuable table is given, showing 

 the yearly rainfall at Adelaide for 59 years from 1839 to 1897^ 

 and the years when the amount was above or below the general 

 average (20"886 inches) for the whole period. 



