April 24, 1913] 



NATURE 



195 



this is confirmed by the anatomy of abnormal speci- 

 mens of the field horsetail in which more than one 

 annulus is present. 



The report of experiments carried out in i<)i2 at the 

 Harper Adams Agricultural College and in Shropshire 

 and Staffordshire contains accounts of inquiries into 

 the effect of pruning and of grass on fruit trees, the 

 wart disease of potatoes, the manuring of grass land 

 for milk, &c. During the past year oats in many 

 parts of the country were badly attacked by the frit-fly 

 (Oscinis frit), and since the life-history of this pest 

 is not fully known, investigations in this direction have 

 been instituted. Although preventive measures cannot 

 be given at present, it may be noted that early sown 

 crops are not so liable to attack as those sown later, 

 and also that a dressing of nitrate of soda helps the 

 plant to recover from initial attack by the pest. How- 

 far the severity of attack depends on the variety of oat 

 has still to be ascertained, but striking differences 

 were observed among the varieties cultivated last year. 



Messrs. E. S. Salmon and C. VV. B. Wright con- 

 tribute a paper to the March number of the Journal 

 of the Board of Agriculture on lime-sulphur wash for 

 American gooseberry mildew. As a result of extended 

 observations it has been found that different varieties 

 of gooseberries differ to a marked degree as regards 

 the susceptibility of the foliage to injury from the 

 wash. It is possible with some varieties, e.g. " May 

 Duke," to spray repeatedly throughout the season 

 with lime-sulphur, at a strength (i-oi sp. gr.) sufficient 

 to prevent the attacks of the mildew, without causing 

 any injury to the foliage. In other cases it seems 

 probable that the foliage of a variety may be resistant 

 to injury from the wash, while showing susceptibility 

 later in the season. Other varieties, such as " Valen- 

 tine's Seedling" and "Yellow Rough," are so sensi- 

 tive that they cannot safely be sprayed with lime- 

 sulphur. 



The report of Stonyhurst College Observatory 

 (Lancashire) for 1912 contains results of meteoro- 

 logical, magnetical, and seismological observations, 

 together with mean and extreme values for the last 

 sixty-five years. Some of the meteorological results 

 for last- year are noteworthy from several points of 

 view. The annual rainfall was 7J in. above the 

 average ; in March the amount was more than double 

 the average, and was the greatest on record for that 

 month. The duration of bright sunshine was nearly 

 410 hours below the yearly average (thirty-two years) ; 

 August had only 50 per cent, of the normal amount, 

 and the maximum temperature was n-6° below its 

 average highest reading. Father Sidgreaves states 

 that owing to the decision of the Meteorological 

 Office to reduce the number of its observing stations 

 the connection of Stonyhurst with the office would 

 cease at the end of March, but we are glad to learn 

 that the automatic recorders are to remain there, and 

 will be kept in active service. This observatory is 

 one of those adopted by the first Meteorological 

 Committee (1867) for the continuous registration of 

 meteorological phenomena at important positions in 

 the British Islands. In the report of the Meteoro- 

 logical Committee for the year ended March 31, 1912, 

 it was explained that the urgency of questions con- 

 NO. 2269, VOL. 91] 



nected with the upper air had decided it to with- 

 draw in some cases the grants made for the continu- 

 ance of observations in the old form. 



Part 5 of the first volume of the science reports of 

 the Tohoku Imperial University, Japan, contains a 

 paper on the magnetic susceptibilities of iron, steel, 

 nickel, and cobalt up to temperatures of 1300 C, by 

 Profs. Honda and Takagi. The method used depends 

 on the measurement of the force under which the 

 maenetisable material moves from a weak to a strong 

 part of the magnetic field in which it is placed. The 

 field was provided by a small du Bois electromagnet, 

 and the force w-as measured by means of a delicate 

 spring balance. The materials tested were placed in 

 a small magnesia capsule surrounded by an electric 

 furnace. The temperature of the specimen was deter- 

 mined by means of a platinum platinum-rhodium 

 thermo-junction standardised by the use of the melting- 

 points of lead, zinc, antimony, copper, and nickel. As 

 the result of their investigations, the authors find that 

 Curie's law, according to which the susceptibility 

 should vary inversely as the absolute temperature, 

 does not hold for nickel below 500 C, does not hold 

 over any extended range of temperature for cobalt, 

 and is not even approximately true of iron or steel in 

 what is known as the y state above 8oo° or 900 C. 



Messrs. Townson and Mercer, Ltd., have sent us 

 a specimen of a new type of inorganic filter for labora- 

 tory purposes. The filter is cone-shaped, and is under- 

 stood to be composed of powdered alundum (a variety 

 of fused alumina) cemented by firing with siliceous 

 material. It is sufficiently porous to allow of rapid 

 filtration, is not sensibly affected by solutions of 

 common chemical reagents, and withstands the usual 

 temperatures employed in the laboratory. For use, it 

 is fitted into an ordinary glass funnel by means of 

 rubber tubing, and connected with a filter-pump. 

 Paper filters can be employed with it, or not, accord- 

 ing to requirements. One of the chief advantages is 

 that the filter can be used for quantitative determina- 

 tions in the same manner as a Gooch type of filter, 

 but without the trouble of preparing an asbestos layer 

 every time. A light aluminium stand is supplied for 

 convenience in weighing. How far any difficulty of 

 cleansing or liability to fracture might prove trouble- 

 some, only extended trial could show; but a few 

 summary experiments indicate that the filters will 

 probably be very convenient for many gravimetric 

 chemical operations. The makers are the Norton 

 Company, Massachusetts. 



In the course of an article on the relation of 

 engineering and architecture, The Builder for April 

 11 suggests two main considerations as accounting 

 for the division which now exists : one, the public 

 willingness to accept great works of engineering as 

 necessary evils from an assthetic point of view ; the 

 other, the greater extent to which the engineer must 

 be immersed in the practical considerations of high 

 mathematical problems which have to be solved in 

 connection with many engineering works. The latter, 

 it is asserted, tends to the narrowing of the mental 

 point of view. The remedies suggested are the educa- 

 tion of public opinion so that it will demand the 

 assthetic treatment of engineering work, and the 



