September 15, 1904] 



NATURE 



485 



writes that the storm lasted for three hours, and was accom- 

 panied with almost continuous thunder and lightning, and 

 he estimates that at least 12 inches of rain fell during that 

 time. Bridges and houses were washed away, and about 

 a hundred lives were lost in that locality. The storm ex- 

 tended over a considerable area, probably 200 to 300 square 

 miles, and the Guaninicum and Platanillo Rivers each rose 

 33 feet. Mr. Wilson gauged the fall for an hour and a half, 

 during which time nearly 7 inches were measured. 

 Santiago is a station of the U.S. Weather Bureau ; \ve shall 

 therefore hope to receive a fuller account of the storm. In 

 looking through their last published report (1902-3), we do 

 not find any figures equalling the above, but in Symons's 

 ■' British Rainfall for ino- " 3.50 inches are recorded in one 

 hour. The most noteworthy facts appear to be the duration 

 of the great intensity of the fall and the large area over 

 which the storm occurred. 



The Meteorological Council has recently issued part I. 

 of " Climatological Observations at Colonial and Foreign 

 Stations." In the preface Dr. W. N. Shaw states that the 

 council has contemplated for some time the issue of 

 summaries of the observations which they receive from the 

 Toreign Office, the Colonial Oflfice, or directly from the 

 observers in various British colonies and dependencies, but 

 that it has been unable hitherto to carry out the pre- 

 paration of the observations for the press. Mr. E. G. 

 Ravenstein, who was chairman of a committee appointed 

 by the British Association at the Cardiff meeting in 1891 for 

 the collection and discussion of observations from tropical 

 Africa, has, however, been good enough to put together the 

 observations for a large number of stations, and to super- 

 intend the preparation of the summaries. These have now- 

 been issued by the Meteorological Council for the years 

 iQoo-2, with summaries for previous years, and form a verv 

 valuable contribution to the meteorologv of that part of 

 the world. The observations refer chiefly to stations in the 

 Kifyptian Sudan, British East and Central Africa, and 

 Rhodesia. The volume is accompanied by useful sketch 

 maps showing the positions of the various stations. 



Dr. F. M. Exner contributed a useful paper to the 

 \'ienna Academy of Sciences {Sit:b., Heft x., 1903) on a 

 relation between the distribution of air pressure and amount 

 of cloud, based on an examination of the mean values of 

 nventy years' observations. The question to be solved was 

 with what distribution of pressure, w-ith a west wind of 

 given strength, has Vienna a certain amount of cloud or 

 r.iinfall. The result of the investigation showed that when 

 the air flowed from an area of steep barometric gradients 

 to one of slight gradients, it was accompanied by bad 

 weather, and vice versA. The reason is that in the first case 

 more air flows towards the locality than flows away from it 

 horiEontally, so that a portion of it finds its way to the upper 

 strata, while in the second case the opposite occurs. The 

 same rule would apply not only to a west wind, but would 

 hold good for wind from any quarter. The paper is illus- 

 trated by a series of charts. 



Messrs. S. Hirzei., of Leipzig, announce a new publi- 

 cation bearing the title Jahrhuch der Radioaktivitixt und 

 EU'ktronik, to be edited by Dr. J. Stark, of Gottingen. 

 F.ach volume will be issued in four quarterly parts. 



The mathematical and scientific section of the Imperial 

 Academy of Sciences, Vienna, announces a prize of 

 2000 krone to be awarded for the best thesis embodying 

 " an improvement in our knowledge of the hysteresis of 

 dielectrics." The competition will close on December 31, 



ll|0(.. 



NO. 1820, VOL. 70] 



No. 16 of the Physikaliscbe Zeitschrift contains several 

 papers dealing with radio-activity. F. Paschen shows 

 that when the kathode rays produced by radium are caused 

 to impinge from above upon a photographic plate placed 

 film downwards on a small sheet of platinum, an intense 

 blackening is produced in the negative which corresponds 

 in outline with the metal. That this effect is due to a 

 secondary radiation,- and is not caused merely by reflection 

 of the kathode rays from the platinum, appears to be proved 

 by the fact that when these rays are directly transmitted 

 through a sufficiently thin plate of the metal, the darken- 

 ing beneath the metallic film is much more intense than 

 elsewhere. It is the 7 rays which seem to be mainly re- 

 sponsible for the secondary radiation. Mr. H. A. Bumstead 

 has carefuUv investigated the nature of the radio-activity 

 induced in a negatively charged wire by exposure to the 

 atmosphere. He concludes that the atmosphere contains 

 principally the emanation of radium, but that the thorium 

 emanation is also present to an extent varying largely with 

 conditions such as the temperature and stillness of the air. 

 On the other hand. Dr. E. F. Burton considers that the 

 radio-active emanation which is evolved on heating raw 

 petroleum is due solely to radium, and that a small quantity 

 of radium itself is present in the oil. Miss C. Bohm-Wendt 

 describes measurements which show that the amount of 

 ionisation produced by polonium in different gases is in- 

 dependent of the nature of the gas. In this respect, there- 

 fore, polonium resembles radium. 



It has long been a controversial question whether by the 

 action of heat alone the line spectrum of gases can be pro- 

 duced. In the July number of the Atti dei Lincei 

 R. Nasini and F. Anderlini endeavour to give a definite 

 answer to the problem. On subjecting the vapour of iodine 

 to a high temperature in a carbon tube heated in an electric 

 furnace, they found that at slightly above 1000° an emission 

 spectrum is produced which is the inverse of the usual 

 absorption spectrum of iodine vapour. Similarly nitrogen 

 at temperatures above 3000° gives an emission spectrum in 

 which the principal lines characteristic of the element are 

 visible. Under the conditions used it is probable that 

 electrical influences w^ere excluded, and that the spectra 

 obtained were due solely to the high temperature employed. 

 In the same number of the Alii L. Vanzetti has studied the 

 electrolysis of glutaric acid in order to decide w-hether the 

 dibasic aliphatic acids are capable of being converted in 

 this way into polymethylene hydrocarbons, and whether 

 the synthesis of a closed ring can thus be effected. 'Ihe 

 acid ga%'e, however, only ordinary propylene, not a trace of 

 trimethylene being formed. 



VVe have received copies of two interim reports issued by 

 the Engineering Standards Committee. One of the publi- 

 cations contains British standard tables of copper conductors 

 and thicknesses of dielectric ; the other includes the British 

 standard specification for tubular tramway poles. The 

 tables and specification are to be regarded as final, and they 

 will be embodied in the final report of the Engineering 

 Standards Committee, which will combine all specifications. 

 The tables dealing with copper conductors give the British 

 standard sizes of stranded conductors for electric supply, and 

 separate tables are concerned respectively with large, inter- 

 mediate, and small sizes. Other tables provide British 

 standard radial thicknesses for jute or paper dielectric, lead 

 and armour, for underground cables, and British standard 

 radial thicknesses for rubber dielectric, for lead sheathing 

 and armouring. The specification for tramway poles gives 

 full particulars as to construction, length, length of section, 

 outside diameters, minimum thickness, &c., and also as to 



