Fehruart 9, 191 TJ 



NATURE 



48: 



The difficulty of producing definite proof even for 

 elementary physiological principles is exemplified in the 

 two articles on the translocation of carbohydrates in plants 

 contributed by Mr. S. Mangham to Science Progress 

 (October, iqio, and January, 191 1). Formerly the opinion 

 was generallv accepted that, while albuminous substances 

 pass through the sieve-tubes, the carbohydrates travel 

 chiefly, if not entirely, through the parenchymatous cells 

 of the vascular bundle. In 1897 Czapek enunciated the 

 view, which is here affirmed, that the sieve-tubes furnish 

 (he path for rapid translocation of the assimilates as a 

 whole. The problem is discussed both with regard to the 

 structure of the conducting tissues, more especially of the 

 small veins in the leaf, and Jhe results of physiological 

 experiments. The weightiest arguments are derived from 

 the interpretation of Schubert's examination of the leaf- 

 veins and the author's experiments for tracing the sugars 

 in the tissues by the formation of osazones. The latter 

 method is only briefly indicated, but further details of the 

 process and results are promised ; meantime, the author is 

 justified in stating that he has furnished strong evidence 

 in favour of Czapek's theory. 



We have received the Almanac for 191 1 published by the 

 Survey Department of Egypt. It has increased in size, 

 and contains a large amount both of statistical and general 

 information concerning Egypt and the Nile basin. Much 

 information relating to such important matters as taxation, 

 areas of jurisdiction, &c., which is not always readily 

 accessible to the public, is here included. 



In the report upon the rains of the Nile basin and the 

 Nile flood of 1909, published by the Survey Department of 

 Egypt, Mr. J. I. Craig gives full details of the rainfall 

 and its effect on different parts of the river system. He 

 points out that certain anomalous variations of the level 

 of Lake Victoria in 1908 have been definitely traced to 

 instability of the gauge at Jinja, and are not to be con- 

 nected with possible crustal movements. The number of 

 stations has increased, there being now 96 in Egypt and 

 the Sudan, while data from 121 other stations in surround- 

 ing regions are utilised. In a final chapter he summarises 

 recent investigations into the possibility of predicting the 

 character of the flood. 



In the January number of the Geographical Journal 

 Prof. T. Park describes the area affected by the Tarawera 

 eruption in New Zealand in 1886, its erosion since that 

 date, and the development of new vegetation. The sheet 

 of grey ash which then covered the dissected tableland on 

 the shores of Bay of Plenty has now been deeply scored 

 by rain, and many points of interest, such as the distribu- 

 tion of the black andesitic ash, may now be seen. Since 

 1890 the growth of vegetation, mainly bracken, tutu, 

 veronica tree fern, blue gum, and acacia, has been rapid, 

 some of the gum trees being now more than 30 feet high. 



To the Bulletin of the St. Petersburg Academy of 

 Sciences of December i, MM. Dudetzky and Weinberg 

 communicate a short paper on the microstructure of hail- 

 stones. These were collected during a thunderstorm at 

 Tomsk (Siberia) on June 12, 19 10, were mostly spheroidal 

 in form, and generally 7 to 10 mm. in size. Their con- 

 centric spherical layers were alternately opalescent and 

 transparent, and divided according to the rays by a quantity 

 of air-bubbles, frequently oblong in shape. Many of the 

 stones consisted only of one layer, sometimes quite trans- 

 parent, in other cases milky. An interesting peculiarity 

 presented itself in some of the stones, formed of several 

 spherical layers, viz., the eccentricity of the milky central 

 grain. This occupied a lateral part of the hailstone, and 

 NO. 2154, VOL. 85] 



often formed but part of a sphere. In the stones examined' 

 it was difficult to indicate any relation between their 

 crystalline and physical structure. The only fact that could 

 be drawn from the visual study of the images of the thin 

 plates on a screen was a certain enlargement of the 

 crystalline grains with distance from the centre of the 

 central layer. 



According to a paper by Dr. L. A. Bauer in the 

 January number of the American Journal of Science, it i» 

 proposed to take observations of the value of the gravita- 

 tional acceleration on board the American magnetic ship 

 Carnegie during her future voyages, beginning at Cape 

 Town in April next. The method to be adopted is that 

 suggested by Guillaume in 1894, and used on land by 

 Mohn and at sea by Hecker. It consists in the observa- 

 tion of the height of the barometer and the boiling point 

 of water with mercury thermometers of special construc- 

 tion, or with resistance thermometers. The principal 

 difficulty in obtaining accurate results is the " pumping " 

 of the barometer owing to the motion of the ship, and this, 

 it is hoped, will be overcome by the construction and 

 mounting of the instrument. The barometers and thermo- 

 meters are to be compared at intervals with standard 

 instruments, and observations in port are to be made on 

 land and on water, and are to be compared with the results 

 of pendulum observations wherever it is possible. By 

 these means Dr. Bauer hopes to secure results free from 

 the objections which can be urged against those of Hecker. 



The new convertible Balopticon lantern, of which a 

 catalogue has been issued by the Bausch and Lomb Optical 

 Co., Thavies Inn, London, E.C., is designed for the pro- 

 jection of lantern-slides by transmitted light, opaque 

 objects by reflected light, and for microscopical and 

 vertical projection by the addition of the necessary attach- 

 ments. The apparatus appears to be very ingeniously 

 devised, as by its aid almost any projection work may be 

 carried out efficiently that would otherwise require much 

 larger and more complex arrangements. It must not be 

 forgotten, however, that the brilliancy of the picture to 

 be obtained with any projection apparatus depends 

 primarily on the power of the source of light, so that the 

 illuminant, particularly for opaque objects, should be an 

 efficient one. In the present instance this point has not 

 been overlooked, and as, in addition, the optical parts are 

 of a high order, the results to be obtained are in every 

 way satisfactory. Each one of the above-mentioned 

 methods of projection may be obtained almost instantly 

 as required, so that for lecture purposes, w^here objects of 

 a varied character are to be shown, the apparatus can be 

 used with ease. 



The Builder for January 27 contains an interesting 

 account of a method of strengthening a bridge by means 

 of sheathing the steel trestles with reinforced concrete. 

 The bridge operated on is that carrying the Wabash Rail- 

 way over the River Missouri. Originally designed for the 

 moving loads prevalent at the time, the trestles were quite 

 inadequate for modern traffic requirements. After pre- 

 liminary experiments, all the columns have been converted 

 into octagonal reinforced concrete columns by applying 

 concrete embedding a spiral coil of No. 6 American gauge 

 wire wound with a pitch of 2 inches. The column bases 

 consist of a rectangular concrete block reinforced bv a 

 network of steel rods near the outer surfaces. The struts 

 bracing the four columns in each tower have been, cased 

 in concrete, the concrete being reinforced by eight half- 

 inch rods, around which is a wrapping of wire netting. 

 The connections between columns and struts are stiffened 

 by reinforced concrete brackets. The concrete used was 

 mixed in the proportions of one part Portland cement to 



