fULY 6, igi i] 



NATURE 



19 



m are characterised by distinct vernal and autumnal 

 habits. 



Iiil question having been raised whether the timber 

 from teak plantations is as strong as that from natural 

 forests, specimens from trees grown in Burma were sub- 

 ! to a series of tests, with the results recorded by 

 Mr. R. S. Pearson in Forest Bulletin No. 3 published by 

 the Government of India. The samples were, of course, 

 similar in dimensions, and care was taken to get them as 

 uniform as possible with respect to moisture content. Only 

 in the case of transverse strain did the timber of natural- 

 grown teak give a higher coefficient, and then the differ- 

 ence was small enough to be negligible for practical pur- 

 poses. Another Bulletin (No. 2), issued with the former, 

 provides a set of diagrams and curves, prepared by Mr. 

 F. A. Leete, to show the relation between age, girth, 

 number of stems, and height of teak trees in fully stocked 

 plantations. The data may be used to determine whether 

 any given area is suitably stocked or if thinning is 

 required. 



In La Ge'ographie for April M. C. Rabot summarises 

 his own work and that of others relating to the superior 

 limits in altitude of forest trees in Scandinavia, and comes 

 to the conclusion that the retreat of these upper limits 

 is to be attributed to climatic variation or, more exactly, 

 a lowering of the summer temperature, which has been 

 estimated at 2.5° C. 



In the Transactions of the Royal Society of Canada 

 Dr. W. Bell Dawson describes in general terms the scope 

 of the investigations carried on by the Tidal Survey of 

 Canada. An important portion of the work has been 

 the establishment of local bench-marks and the determina- 

 tion of their relation to mean sea-level, since no general 

 system of levels yet exists in the country. A number of 

 these have now been fixed, and are described in a recent 

 (1906) report of the marine department, but their con- 

 nection by lines of precise levelling is still wanting. 



Messrs. S. Nakamura and K. Honda contribute a 

 lengthy paper to the Journal of the College of Science at 

 Tokio University on seiches in some lakes of Japan. 

 Starting with a Sarasin limnimeter, a simpler type of port- 

 able instrument was found desirable, and each of the 

 authors produced one which was found to be well suited 

 to the investigation in hand. Large-scale records of the 

 curves obtained with these instruments are given in 

 facsimile, and these show the very marked oscillations of 

 the water set up by violent thunderstorms passing over the 

 lake while the record was being taken. 



In the Arkiv for Matematik, Astronomi och Fysik of 

 Stockholm, Band 6, No. 40, Mr. O. A. Akesson puts for- 

 ward a method for determining the direction of ice-drift in 

 the neighbourhood of the Pole. Supposing such drift to 

 be rectilinear and uniform, he utilises four altitudes of the 

 sun taken in pairs at about six hours' interval, as long a 

 period as practicable separating the first and last pair. 

 The Greenwich times of the observations are supposed to 

 be known, and, following the method employed by Prof. 

 Charlier, the position of the first point and the direction 

 and rate of drift are obtained. An example from the voyage 

 of the From, when ice-bound from February, 1893, to 

 August, iSg5, is given in illustration of the method. 



At a meeting of the Research Department of the Royal 

 Geographical Society, Dr. Strahan presented the fourth re- 

 port on the investigation of British rivers, which dealt 

 NO. 2175, VOL. 87] 



with the Exe, the Creedy, and the Severn. Gauge read- 

 ings and discharges had been taken frequently, and an 

 interesting determination of the bottom-load moved by the 

 Exe in each of the past seven years was included. The 

 rainfall has also been studied to obtain the ratio of the 

 run-off for the river system and for different tributaries. 

 This most important investigation can only advance slowly 

 on account of the lack of local observations having any 

 considerable continuity and being satisfactorily comparable. 

 Even under the present arrangements, it is difficult to 

 ensure brief flood waves being adequately recorded at all 

 stations, but the results testify the importance of the 

 inquiry and the need for continuing it on as wide a basis 

 as possible. 



The meteorological charts for July issued by the Meteor- 

 ological Committee contain, inter alia, timely and useful 

 notes on the cyclonic storms of the Indian Ocean. During 

 that month the south-west monsoon dominates the weather 

 conditions over the Bay of Bengal and the Arabian Sea, 

 and storms over the head of the bay are of comparatively 

 frequent occurrence ; the force of the monsoon in the 

 Arabian Sea attains at times thirty to forty-four miles an 

 hour. In the South Indian Ocean cyclonic storms are 

 (so far as available observations show) practically non- 

 existent in July ; only one trustworthy storm track is 

 shown there on the chart during a 38-year period. The 

 interesting synoptic weather charts over the North Atlantic 

 for June 8-14 show that a cyclonic area which was formed 

 off Newfoundland on June 11 moved steadily eastward, and 

 at the close of the period was beginning to influence the 

 weather on our extreme western and south-western coasts. 



An interesting contribution to Symons's Meteorological 

 Magazine for June, by Mr. R. C. Mossman, now attached 

 to the Argentine Meteorological Office, refers to the prob- 

 able rainfall in the north-east of England during the 

 present summer. On comparing the rainfall at Cordoba 

 for the first quarter of the year for the thirty-three years 

 1878-1910 with that of the north-east of England for the 

 third quarter, it is seen that the values are generally the 

 reverse of each other, i.e. when the rainfall at Cordoba 

 is in excess of the normal during the first quarter, it is 

 in defect over the north-east of England in the third 

 quarter, and vice versa. During the first quarter of this 

 year the rainfall at Cordoba was only 46 per cent, of the 

 normal. So far as these statistics go, therefore, there is 

 a distinct suggestion that the present summer (July to 

 September) will have a rainfall in excess of the normal 

 over the north-east of England. 



The summary of the weather for the first six months 

 of the present year, which has just been issued by the 

 Meteorological Office, shows that the mean temperature 

 was slightly in excess of the average in all parts of the 

 United Kingdom, taking the period as a whole. The 

 absolute highest temperature in any district during the six 

 months was S4 , in the north-east of England, and 80° 

 has been exceeded in every district except in the north of 

 Ireland and in the Channel Islands, whilst the lowest 

 temperatures are below 20 in every district except in the 

 Channel Islands, the absolutely lowest reading being 11°, in 

 the east of Scotland. The largest aggregate rainfall for 

 the six months January to June inclusive is 24-02 inches, in 

 the north of Scotland, which is 0-58 inch more than the 

 average ; but this is the only district with an excess of 

 rain except the east of England, where the aggregate was 

 10-33 inches and the excess 0-15 inch. The smallest aggre- 

 gate rainfall in any district is 8-31 inches, in the Midland 



