[68 



NA rURE 



[December io, 1908 



variety, that has replaced the native or " country " 

 variety. In some districts quick-growing millets are 

 planted as a catch-crop. Mr. C. K. Subba Rao is re- 

 sponsible for the pamphlet on fig cultivation. The red, 

 loamy soil and temperate climate of Bangalore and Bellary 

 provide conditions suitable for the fig tree. Artificial 

 pollination, known as " caprification," is not practised, 

 nor are the figs dried for market, owing, presumably, to 

 the ready sale that exists for the fresh fruit 



The results of two years' experiments obtained on 

 various estates and at the sugar experiment station, 

 Jamaica, are reviewed by Mr. H. H. Cousins in his re- 

 port recently published by the Board of Agriculture. A 

 fact of considerable interest is the value of small dressings 

 ol lime on the sugar plantations. In accord with manurial 

 experiments elsewhere, the application of a manure rich 

 in nitrogenous matter is essential and profitable. With 

 regard to new seedlings of value, the well-known variety 

 B. 20S has proved to be eminently satisfactory for all dis- 

 tricts, but even better results are expected from seedlings 

 raised on the island within the last five years. 



From Prof. Haberlandt's laboratory at Graz there has 

 been issued another paper on the perception of light by 

 plants, that is published in the Sitzungsberichte der kaiser- 

 lichen Akademie der Wissenschajten, Vienna (vol. cxvii., 

 part ii.). The author. Dr. K. Gaulhofer, has studied the 

 epidermal cells of the leaves of certain plants that take 

 up a fixed light position, and suggests that an explanation 

 may be found in the presence of pits or clefts in the cell 

 walls acting as light distributors, in a similar manner to 

 Prof. Haberlandt's " lichtsinnesorgane." The rays of 

 light impinging on the edges of the pits are deflected, and 

 consequently, underneath the pits, shadows are produced. 

 Good instances of such pits occur in Aporrhiza paniculata 

 and Banisteria splendeiis, while Hyperbaena laurijoUa and 

 Ahuta concolor show well-marked clefts. The combina- 

 tion of pits and curved cell wall in Cocculus laurijoUus 

 will repay e.xamination. 



The increasing use of artificial manures in South 

 Australia — a sure sign of advance in agricultural methods 

 — forms the subject of an interesting article in a recent 

 issue of the journal of Agrictdture of South Australia. 

 During the last ten years the total acreage under cereals 

 has remained fairly constant, but the proportion receiving 

 artificial manures has increased from 12 per cent, in 1898 

 to 68 per cent, during the present year. The steady and 

 continuous nature of the increase is seen in the following 

 table : — 



Total area Area receiving 



1900 

 1902 

 1904 

 1906 



c-ils, 



2,148,000 

 2,298,000 

 2,144,000 

 2,154,000 

 2,063,000 

 2,154,000 



230,000 



500,000 



845,000 



1,170,000 



1,321,000 



1,456,000 



Superphosphate is by far the commonest artificial manure 

 used ; at present it is imported, but as large quantities 

 of mineral phosphates are known to occur in South 

 Australia, there seems no reason why it should not be 

 made on the spot. 



Mr. H. Ling Roth, honorary curator of the Bankfield 

 Museum, Halifax, issues as one of his periodical Bulletins 

 an interesting study of "Trading in Early Days." He 

 suggests that the most primitive form of trading is to be 

 found in the exchange of presents among certain members 

 of savage tribes. He discusses the questions connected with 



NO. 2041, VOL. 79] 



silent trade, secret bargaining, early forms of transport 

 and markets, the evolution of notation and currency, all 

 illustrated by excellent photographs from the collections 

 under his charge. 



The University of Philadelphia has undertaken a series 

 of excavations in the Isthmus of Hierapetra, in Crete, the 

 results of which for the year 1906, and so far as the site 

 of Vasiliki is concerned, are described in the second volume 

 of the Transactions by Mr. R. H. Seager. The remains 

 extend over the second and third stages of the early and 

 the first of the Middle Minoan periods. Though the 

 ground has suffered much from denudation, some valuable 

 discoveries have been made — a beehive tomb at Hagios 

 Theodores, believed to be the second of its kind belonging 

 to the Bronze age that has been found in Crete ; a series 

 of houses, and much fine pottery. In connection with this 

 last Mr. Seager makes the interesting statement that the 

 mottled ware of the third Minoan period is of a type 

 commonly in use at the present day in south India from 

 Tuticorin to Madras, while that of the fourth period 

 strikingly resembles the modern domestic ware of the 

 Rajput States. The writer, in agreement with Profs. 

 Ridgeway, Bosanquet, and others, regards as an early 

 form of currency a number of curious axes, these weapons 

 being obviously too small and weak to serve any industrial 

 or military purpose. 



Dr. J. M. Pernter has sent us the year-book of the 

 .'\ustrian Central Meteorological Office for 1906. The 

 number of stations then included in the system was 409, 

 of which forty-two ranked as observatories or stations of 

 the first class, e.g. possessing self-recording instruments. 

 The observations are arranged according to the class of 

 station ; some include hourly values, while at others tri- 

 daily observations or simply mean results are given ; 

 several organisations, including the Hungarian, publish 

 their observations separately. The Central Office takes 

 part in the international monthly balloon ascents for the 

 investigation of the upper air, and also issues weekly re- 

 ports of earthquake phenomena observed at several of the 

 principal observatories. An appendix contains valuable 

 discussions (i) of thunderstorms and hail in Bohemia in 

 1905 and 1906, by Dr. F. Augustin, and (2) measurements 

 of solar radiation at Vienna from March, 1904, to Sep- 

 tember, 1906, with Angstrom's compensation pyrhelio- 

 meter. The results are exhibited both statistically and 

 graphically by Dr. R. Schneider, and show, inter alia, that 

 the solar intensity on a perpendicular surface of i cm", 

 attains its ma.ximum of 740 gram calories per diem at the 

 beginning of June, and its minimum of 245 calories per 

 diem in December. 



Those who have the designing of glass gauges and other 

 glass apparatus to withstand high pressures will find a 

 number of useful tables of breaking stresses of tubes sub- 

 jected to internal pressure and of filaments subjected to 

 tension in Communication No. 106 from the Physical 

 Laboratory of Leyden, by Prof. Kamerlingh Onnes and 

 Dr. Braak. Although the numbers in the tables differ 

 considerably from each other in many cases, it seems that 

 tubes break when the pressure inside makes the maximum 

 tension in a direction perpendicular to the axis equal to 

 about 5 kilograms per square millimetre, and that fila- 

 ments in tension break at about 17 kilograms per square 

 millimetre at ordinary temperatures, and at about 30 kilo- 

 grams at the temperature of liquid air. 



In X-ray work it is necessary that the current through 

 the tube shall be unidirectional. There are devices in 

 existence by means of which the behaviour of the tube 



