April 27, 191 1] 



NATURE 



291 



fiiE Seismolog^ical Society of America, which owes its 

 toundation to the interest aroused by the Californian earth- 

 quake of 1906, has recently issued the first number of its 

 quarterly Bulletin. Most of the short papers which it 

 contains are devoted to the study of seismology in the 

 United States, to the difficulties under which its prosecu- 

 tion labours, and to suggestions for organised work in the 

 future. Among the papers of permanent interest may be 

 mentioned Mr. H. F. Reid's account of the earthquakes 

 felt in Central New Mexico in 1906 and 1907, and the list 

 of seismographs known to be at work on the American 

 continent, a list which includes no fewer than thirty-five 

 Wicchert pendulums, twenty-nine Bosch-Omori pendulums, 

 and nine Milne seismographs. Prof. Branner, in discussing 

 the relations between earthquakes and the growth of faults, 

 suggests the need for distinguishing between faults which 

 are now active and others which have apparently reached a 

 condition of stability, and he points out the useful work 

 which might be carried out in this direction by the 

 organised study of Californian earthquakes. 



The daily and yearly period of rainfall at Trieste is 

 discussed by Dr. E. A. Kielhauser in an interesting paper 

 laid before the Vienna Academy of Sciences in November 

 last, based on eleven years' readings of the self-recording 

 rain-gauge at the observatory (1896-1906). Among the 

 many points referred to we may mention that the rain-curve 

 of the amounts for separate hours shows that it is made up 

 of a large number of waves of short periods. In addition 

 to the most prominent extremes of the absolute maximum 

 (iih.-i2h. p.m.) and the absolute minimum (iih.-i2h. 

 a.m.), fifteen relative maxima and minima are exhibited. 

 In spring and winter, the hours of 5 a.m. to i p.m. are 

 relatively dry, while in summer and autumn they are 

 relatively wet ; for the other hours the reverse naturally 

 obtains. At all seasons of the year the duration of rainfall 

 is greatest at night-time. The annual rainfall is 39-7 inches 

 (mean of sixty years, 428 inches). The driest months are 

 February, April, December, and especially January ; the 

 wettest months are May, June, November, and especially 

 September and October. The driest month of the eleven- 

 year period was February, 1896 (007 inch), the wettest, 

 October of the same year (107 inches). 



The April number of the Journal of the Rontgen Society 

 contains a paper by Dr. W. Salomonson, of Amsterdam, 

 on the induction coil, considered mainly from the point of 

 view of the Rontgen-ray photographer. It is well illus- 

 trated by reproductions of photographs of the spark and 

 of the primary current taken with a string galvanometer 

 or an oscillograph. These show clearly that, as the 

 capacity of the condenser in the primary is increased from 

 a very small value, the time taken for the primary current 

 to fall to zero at first decreases, then increases, in agree- 

 ment with the theory of Mizuno. With an interrupter 

 working in hydrogen or coal gas, the time of fall of the 

 jprimary current may be reduced to 00002 second. Experi- 

 ments with a new coil, by means of which photographs of 

 the heart and lungs can be taken in 001 second, show 

 fhat the spark is shaped like a corkscrew, and that it 

 passes before the magnetic field due to the current in the 

 primary has disappeared. 



To those who are so unfortunate as to have to deal with 



»!ectrical apparatus which has been flooded, the account 



f the steps taken by the railway and other companies to 



i- an and dry the apparatus submerged during the Pari.s 



floods of 1910, published in The Electrical Review for 



•April 14, will prove useful. It is compiled from the re- 



>rt of the Socidt^ des Electriciens, which relates to more 



NO. 2165, VOL. 86] 



than a thousand pieces of apparatus which were dried 

 satisfactorily. The apparatus was first washed either with 

 water, or, if battery acid had attacked it, with dilute acid, 

 then water, then weak alkali, then water. If oil had got 

 into the apparatus it was first washed with benzoline. Any 

 method of drying, if properly applied, was found effective. 

 Fixed machinery was dried either by an air blast or by 

 fires underneath, in the first instance, and the process com- 

 pleted electrically. Portable machinery was treated in 

 ovens gas or steam-heated to 120° C. at atmospheric, or 

 to 70" C. at reduced pressure. A 6o-kilowatt direct-current 

 generator gave up two gallons of water in the drying pro- 

 cess. Storage cells appear to have come through the floods 

 with very little deterioration. 



Messrs. Carl Zeiss (London), Ltd., have recently 

 introduced the following novelties in optical instruments : — 

 Mayer's new dissecting microscope has a characteristic 

 form of exceptionally large stage, and can be fitted with 

 either monocular or binocular observing systems. It can 

 also take a stereocamera and drawing apparatus. Zeiss's 

 field-glasses are made in a new form, possessing increased 

 light-transmitting power combined with exceptionally large 

 field. Strict alignment of the lenses is secured by casting 

 the hinges and body in one piece. Telescope spectacles 

 are for extreme myopia (10—20 dioptres), and give a field 

 of more than 40°. For astigmatism a special form is pro- 

 vided. A new level is of small dimensions but of extreme 

 sensitiveness. The bubble is observed by a reflecting 

 prisma, which shows images of the semicircular ends of 

 the bubble. In adjusting the instrument, these semicircles 

 are brought into contact along their diameters. All axes 

 are truly cylindrical. The telescope is hermetically sealed 

 up, and by means of a transferable eye-piece can be read 

 from either end. The instrument is packed in a case about 

 8 inches by 5 inches by 25 inches, and the accuracy equals 

 that of a 12-inch or 14-inch level of ordinary type. The 

 Cardioid condenser is for dark-ground microscopical 

 illumination, and is chiefly for studying colloidal matters. 

 It gives a narrow extreme annular illumination the rays 

 of which reunite in the plane of the object. Colloidal gold 

 particles of less than 10 nn can be seen moving rapidly 

 in a field illuminated with this device. The oral illu- 

 minator contains a special arc lamp of 5 amperes fitted 

 with a condensing arrangement for dental and mouth 

 illumination. It is also fitted with a special tinted glass 

 for bleaching the teeth. A new illinninating device for 

 operating theatres consists of a powerful automatic-feeding 

 arc lamp of 30 amperes, throwing a strong boam of light 

 upon a large collecting lens. A system of niinois hicaks 

 up and recollects the light so as to C(in(.nii;ii ■ it free 

 from shadows upon the operating table, lln' ;iiiangement 

 is, naturally, chiefly useful when surgical opiiations are 

 performed at night. 



In an article on the central buffer-coupling appearing 

 in Engineering for April 2t, it is stated that there is a 

 distinct tendency towards its adoption in countries where 

 <he 5-foot 6-inch gauge is the standard. In India, where 

 there are some 16,300 miles of s-foot 6-lnch gauge line, 

 the standard coupling is causing ever-increasing trouble. 

 On one line, the renewals necessary to replace one year's 

 breakages necessitated the placing of orders recently for 

 10,000 screw-couplings. As the present standards give a 

 coupling of about the maximum weight which can be 

 handled conveniently by the native staff, it is apparent that 

 relief must be sought either by making use of much more 

 costly material or in making a change in the type of draw- 

 gear. The present trouble arises from the greater hauling 

 capacity of modern locomotives, the iM, ndiii- \i-. of high- 



