64 



NA TURE 



[May 1 6, 1907 



from Hobson's Bay. Mr. J. A.^ Leach directs attention 

 to the value of surface tension in the formation of canyons, 

 a factor hitherto neglected. There is also a contribution 

 to the flora of Australia, describing new or little-known 

 plants, by Prof. A. J. Ewart, who holds the double 

 appointment of the new chair of botanv at Melbourne 

 University and botanist to the Government of Victoria. 



In the Records of the Geological .Survey of India (vol. 

 .\xxiv., part iv.) Mr. R. R. Simpson describes the Jaipur 

 and Nazira coalfields, Upper Assam. The measures are 

 of Middle Tertiary age, and the coals closely resemble 

 in appearance those from the Makum area, but they are 

 somewhat inferior in quality. They burn readily, with 

 considerable llame and great heat. The amount of work- 

 able coal exceeds 20 million tons in the Jaipur field and 

 35 million tons in the Nazira field. The Dikhu River 

 area is the most suitable for the establishment of a colliery. 

 The accompanying view on the Dikhu River, with the 

 Bor Jan landslip in the background, shows the nature of 

 the ground, which is covered by virgin forest with a 

 dense thorny undergrowth presenting the maximum of 



View on Dikhu River ; ihe Bor Jan l.indslip in the back 



ditTiculty to penetration. The difliculties of transport could 

 probably be overcome by means of an aerial wire-rope 

 tramway. Mr. Simpson also has a note on the Makum 

 coalfield between the Tirap and Namdang streams. Other 

 papers in the same issue are on the Kabat anticline near 

 Seiktein, Upper Uurma ; on the asymmetry of the 

 Yenangyat-Singu anticline. Upper Burma; and on the 

 northern part of the Gwegyo anticline. Upper Burma, by 

 Mr. E. H. Pascoe ; and on Breynia nudtittiberculata, an 

 undescribed species from the Nari of Baluchistan and Sind, 

 by Mr. E. Vredenburg. 



Dr. Eredia, assistant in the Meteorological Office at 

 Rome, has undertaken a laborious and useful work in 

 discussing the frequency of wind direction in various parts 

 of Italy from the observations contained in the .•Annals of 

 that office. Part i. refers to the winds of Piedmont, and 

 deals with monthly and seasonal values for various 

 stations. Speaking very generally, winds from the south- 

 west quadrant predominate in winter, while in summer 

 they are south-westerly in Upper, and north-easterly and 

 south-easterly in Lower Piedmont ; in spring and autumn 

 no very marked predominance is exhibited. 

 NO. 1959, VOL. 76] 



In the Bulletin of the Moscow Imperial Society of 

 Naturalists, Nos. i and ;, 1906, Dr. E. Leyst completes 

 his valuable series of statistical investigations of optical 

 phenomena. The results deduced from observations at 

 seventy stations, and including in the aggregate 1308 years, 

 show that the phenomena have a yearly and secular range, 

 and that solar corona: arc observed about five times less 

 frequently than lunar coronsc ; the maximum of the yearly 

 range occurs in spring, and the minimum about July. The 

 corona; are seen more frequently inland than near the sea 

 coast. 



At the request of the seventh International (jeographical 

 Congress, the Danish Meteorological Institute ha^ for some 

 years past published in its year-book of nautical meteor- 

 ology valuable details, accompanied by monthly maps 

 (April-August), of the slate of the ice, compiled from logs 

 of ships and other sources. The summary for iqo(> shows 

 that, as the winter 1005-6 was comparatively mild over 

 Spitsbergen, Barents Sea, and the Kara Sea, and severe 

 over Greenland and parts of Arctic America, the con- 

 ditions of the ice were consequently favourable in the 

 former region and unfavourable in 

 the latter ; in Barents Sea the con- 

 ditions were especially favourable, 

 while in the Greenland Sea the ice- 

 belt was broader, and off Labrador 

 drift-ice was more frequent, than 

 usual. .All things considered, it is e,\- 

 pected that the conditions in 1007 will 

 be rather favourable along the coasts 

 of Greenland, and less so around 

 Labrador and Newfoundland. The 

 most important events of the year in 

 the Arctic regions were the accom- 

 plishment of the North-West Passage 

 by Captain -Amundsen and the attain- 

 ment of latitude 87° 6' N. by Com- 

 mander Peary. 



The revised edition of the Institu- 

 tion of Electrical Engineers Wiring 

 Rules, which has been recently issued, 

 lontains a good many alterations and 

 '-'""''■ a great deal of rearrangement. The 



rules apply only for voltages up to 250 

 volts, the Board of Trade rules being appended and used 

 for the higher pressures. The standard for copper con- 

 ductors is now that of the Electrical Standards Committee 

 instead of Mathiessen's standard, as- in the past. Insu- 

 lation tests are also modified in that the " bending " test 

 has been omitted, though an increase in the length of time 

 for which the pressure test is applied takes its place. 

 This is a distinct advance, as the danger of mechanical 

 rupture was always present when bending cables of any 

 size, and was in very many cases an unnecessary strain 

 on the cable. Bare conductors also are allowed under 

 special conditions. Switches of more than 5 amperes at 

 125 volts when placed in cases are to have their cases 

 lined with asbestos. Dynamos and motors are now placed 

 under separate headings, but transformers are no longer 

 kept separate, being under a combined heading with 

 resistances and choking coils. .At the end of the rules 

 the Electrical Standards Committee's standard for the 

 resistance and weights of copper conductors is defined as 

 follows : — " A wire one metre long • and weighing one 

 gramme having a resistance of 0-1539 E.S.C. standard 

 ohms at 60° F." In addition to the Board of Trade rules 

 for voltages from 250 volts to 650 volts, the Home Office 



