230 



NATURE 



[July 7, 1898 



structed about twenty years ago, and have been in continuous 

 operation ever since. They consist of a series of tanks contain- 

 ing about seven feet of ashes and clinkers, through which the 

 sewage flows. Each set of tanks is used for a week, and then 

 allowed a rest. The sludge settles in the first tank, and, owing 

 to the action of the microbes, the residue, when taken out and 

 placed on the banks, cannot be distinguished from ordinary soil. 

 The quantity is so small that, although none has been removed, 

 there is no accumulation at the present time. The water in the 

 river Weaver, into which the effluent flows, has from time to 

 time been analysed, but no traces of pollution have been detected, 

 and there is no discoloration. 



The Deutsche Seewarte, in connection with the Danish 

 Meteorological Institute, has issued daily synoptic weather 

 charts for the North Atlantic Ocean and adjacent continents, 

 for a year ending November 1893. These charts give a com- 

 plete representation of the state of the weather existing at 8h. 

 a.m. each day, and clearly show the movements of the low- 

 pressure areas and the positions of the barometric maxima, 

 compiled from all available data from land and sea. Synoptic 

 charts for the above district have now been regularly issued 

 (including those for the same district, issued by our own 

 Meteorological Ofiice for 1882-3) since the latter part of 1873, 

 and contain the most necessary materials for elucidating 

 weather changes and for improving weather predictions. The 

 charts are accompanied by a separate Quarterly Weather Review 

 explaining the various conditions, and illustrated by charts 

 relating specially to each period during which any particular 

 system was maintained, and clearly exhibiting the tracks of the 

 various storms or low-pressure areas from west to east, or north- 

 east. Great credit is due to the German and Danish Institutes 

 for the persistency with which this most important work is 

 carried on, as, although some copies are sold, there must be a 

 considerable expense thrown upon them, both as regards the 

 production of the charts and their subsequent discussion ; but 

 the value of the work to meteorological science is beyond 

 question. 



The Director of the Madrid Observatory, Sr. M. Merino, 

 has published the results of the meteorological observations 

 made there during thirty-five years (1860-94). The tables, 

 which have been very carefully prepared and arranged by Sr. 

 F. Cos, show inter alia the monthly and yearly values of all the 

 principal elements and the daily means for each five years. 

 This long and laborious work is the continuation of that 

 published in 1893, which contained the results of thirty years' 

 observations. The absolute maximum temperatures of the 

 various years range from 98°'6 to iii°7, and the absolute 

 minima from 25° -5 to 9°'5. The average yearly rainfall amounts 

 to 1 6 "5 inches, but the quantity varies very considerably in 

 different years. 



The study of the mathematical theory of electricity would 

 appear to be becoming popular in Japan, to judge from the Kiji 

 of the Tokyo Mathematico- Physical Society. In two numbers 

 now before us (vol. viii. parts i, 2) we find no less than three 

 papers on this subject : one by H. Nagaoka, on the strain of an 

 iron ring by magnetisation ; one by E. Sakai, on the distribution 

 of electricity on two excentric cylinders ; and finally an essay by 

 Dr. S. Kimura, on the magnetisation by induction of a rotating 

 sphere or spheroid under a solenoidal distribution of magnetic 

 force. 



" The disruptive discharge in air and liquid dielectrics ' 

 forms the subject of a dissertation by Mr. T. W. Edmondson, 

 of the University of New York {Physical Review, vi. 2). 

 From experiments with different sized spheres immersed in 

 different liquids, Mr. Edmondson finds that the curves repre- 



NO. 1497, VOL. 58] 



senting the relation between the potential difference and the 

 sparking distance are in general approximately' hyperbolas 

 becoming practically straight lines for spark-lengths of over 

 3 mm. While a smaller difference of potential is necessary to 

 produce a discharge through a given distance for large spheres 

 than for small ones when the spheres are close together, for 

 longer distances the dielectric is electrically stronger for large 

 than for small spheres. Mr. Edmondson gives a table of the 

 dielectric strengths of various substances ; those for air, obtained 

 with spheres, being considerably higher than that obtained by 

 Macfarlane for planes. Both electrostatic and alternating dis- 

 charges are considered. 



A USEFUL summary of the present state of knowledge of the 

 properties of Becquerel rays, in relation to Rontgen rays, is 

 given by Mr. Oscar M. Stewart in the April number of the 

 Physical Review. With reference to these radiations from 

 various chemical substances, it is concluded : " As these rays can 

 be reflected, refracted and polarised, there can be no reasonable 

 doubt that they are transverse ether waves. Interference alone 

 is left to be established to confirm this, but owing to the extreme 

 feebleness and short wave-length it is doubtful whether it can 

 be shown. . . . These rays, like X-rays, are not homogeneous. 

 They have all the properties that X-rays possess, such as photo- 

 graphic action, exciting fluorescence, making gas conductors, 

 and exciting thermo-luminescence. . . . The similarity in the 

 behaviour of the X-rays and Becquerel rays certainly presents a 

 strong argument in favour of the theory that X-rays are short 

 transverse ether waves." In connection with this subject, it 

 should be mentioned that the articles which have appeared on 

 the subject of the discharge of electrified bodies by X-rays are 

 briefly reviewed by Mr. Clement D. Child in Nos. xxiii. and 

 xxix. of the Physical Review (1897), and supplemented with 

 some results of his own upon the effect on the rate of discharge 

 produced by a variation in the density of the air surrounding 

 the electrified body. 



Papers on miscellaneous results of recent work of the Divi- 

 sion of Entomology of the U.S. Department of Agriculture 

 appear in Bulletin No. 10 (new series). The articles are of 

 interest to economic entomologists, and of importance to agri- 

 culturists and fruit-growers. Among the general notes is one 

 on a lead-boring insect. Examination of a lead tank which had 

 leaked showed that the metal had been pierced with holes by 

 the larvae of some species of beetle of the genus Lyctus. This 

 is the third case which has come under Dr. L. O. Howard's 

 notice of insects which bore into lead. In one case a Cossus 

 larva bored its way through a large leaden bullet, which was 

 embedded in an oak tree in which the larva was living ; and in 

 another, a coleopterous larva bored its way through a piece of 

 lead piping. 



An important memoir, containing the results of a detailed 

 craniological investigation, has just been published in the 

 Transactions of the Wagner Free Institute of Science of Phila- 

 delphia (vol. v.). The memoir is the last of the late Dr. 

 Harrison Allen's many contributions to the knowledge of organic 

 forms and their modifications, and entitled "A Study of 

 Hawaiian Skulls." The concluding remarks express clearly 

 the scope of the contents ; they are as follows : — " In the study 

 just completed I have described a new graphic method of col- 

 lating measurements. I have endeavoured to establish the 

 proposition that the difference between the crania called here 

 the ' cave and the coast crania ' are not due to race but to 

 methods of living, and in some degree to differences of mental 

 strength in individuals. The cave series represents the domin- 

 ating and superior type, and the coast series the weak and con- 

 quered type. I have suggested that some of the contrasts that 



