March 9, 191 1] 



NATURE 



53 



Finus Khasya, and Quercus Junghuhnii. In several of the 

 associations, epiphytes, chiefly orchids and ferns, are a 

 characteristic feature ; Dischidia Rafflesiana, Agapetes 

 Hosseana, and Rhododendron Veitchianuin are notable 

 epiphytes. Mr. Craib's list, which is confined to the 

 Polypetalae, contains a number of species new to science, 

 and a type of a new genus, Pittosporopsis, in the family 

 Icacinaceje. A very large preponderance of species in the 

 family Leguminosas is due partly to the number of genera 

 and partly to the variety of species in the genera 

 Desmodium, Crotalaria, Cassia, and Bauhinia. 



In the Cairo Scientific Journal for January, Mr. W. 

 Cartwright has an article on the control of the cotton 

 aphis, thus adding one more to the many useful communi- 

 rations relating to cotton cultivation which have appeared 

 in that journal during the past four years, during which 

 liut little has been done officially to promote research in 

 ihis important field. 



In a recent paper (Bull, de I'Acad. Imp. de Sci. de St. 

 Pctersbourg, 19 ii, No. 2) Prince Galitzin discusses the 

 records obtained at Pulkowa of the great earthquake of 

 January 3-4. He finds that the epicentre was situated in 

 lat. 43° 14' N., long. 78° 24' E., an estimate which agrees 

 closely with that obtained from the records at Eskdale- 

 muir of lat. 42° N., long. 77° E. Both points lie close 

 to Lake Issyl-kul, and to the epicentral area of the great 

 Vyernyi earthquake of June 9, 1887. 



The seismological bulletins of the observatory at 

 Zikawei for November and December, 1910, consist of 

 registers obtained from Omori and Weichert pendulums. 

 The former weighs about 15 kilos., and the latter about 

 1200. In December the heavier of these instruments gave 

 twenty-three records, whilst the lighter only gave eighteen. 

 Three out of the twenty-three seem to be peculiar to 

 Zikawei, whilst the remaining twenty were also recorded 

 in Great Britain, and probably at most stations in the 

 world. 



A PoruLAR article by a resident at Innsbruck, the capital 

 of Tyrol, on the Fohn wind as it strikes an observer, 

 appears in Symons's Meteorological Magazine for February. 

 This blows at times with considerable force, sweeping 

 northwards from the Brenner Valley as a warm, dry wind, 

 raising clouds of dust in its track. If it is summer, the 

 atmosphere becomes stiflingly hot, if winter, the keen, 

 frosty air turns mild srd close ; and it sometimes exerts 

 a depressing influence on the nervous system. From 

 iwenty-five years' observations supplied by Dr. H. v. 

 Kicker, Innsbruck has an annual average of forty-three 

 days of Fohn ; it is most frequent in spring (seventeen 

 days) and autumn (eleven days). It generally lasts one 

 or two days ; twice in the above period it lasted eight 

 days. On vegetation it has its advantages, e.g. Inns- 

 bruck owes its crops of maize to it, and some floral types 

 from the inter-(ilacial {>eriod still survive in the Inn Valley. 

 Its attacks are mild compared with those in certain Swiss 

 \alleys, where it sometimes uproots trees by its fury. 



In tha Australian Monthly Weather Report for March, 

 'Oio, Mr. H. A. Hunt gives a very interesting account of 

 a hurricane of exceptional severity that visited the Fiji 

 group of islands on the 24th and 25th of that month. The 

 storm was a remarkable one, and its track can be followed 

 for soir>» ::;'-o miles from Fiji to Now Caledonia, Norfolk 

 Island, and the North Island of New Zealand, where it 

 arrived on the morning of the 30th. The harbour master 

 at Suva states that its approach was quite unexpected ; 

 the heat was excessive, but the barometer gave scarcely 

 NO. 2158, VOL. 86] 



any warning. At midnight it was falling ; at 2h. a.m. it 

 stood at 29"oo in., and the easterly wind was increasing, 

 with heavy rain. At 3h. a.m. it was blowing with hurrf- 

 cane force, and sheets of iron were flying from all directions 

 between E. and N.E. ; at 4h. a.m. the barometer had 

 fallen to 28*50 in., and then began to rise. At Levuka 

 there was a calm of about ten minutes as the votex passed 

 over the town, with a complete change of direction, but at 

 Suva the wind simply backed from E. to N.N.E. as the 

 barometer rose. The isobaric charts show that the storm 

 followed the usual track, moving in a W.S.W. direction 

 until caught in the easterly atmospheric drift of mid- 

 latitudes, when it curved to the south-east. 



In the January number of the American Journal of 

 Science appears a communication by Dr. L. A. Bauer on 

 gravity determinations at sea, in which he discusses the 

 results obtained by Dr. Hecker in 1901, 1904, and 1909, and 

 indicates the direction in which efforts are being made to 

 attain more satisfactory results during the cruise of 

 Carnegie, starting from Cape Town about April, 191 1. In 

 spite of the most elaborate precautions which were taken 

 in Hecker's trips, trouble was experienced with the 

 boiling-point thermometers employed to determine the 

 atmospheric pressure in order to compare it with the 

 height of the mercurial column, which, under the same 

 conditions, changes with variations of gravity. Experi- 

 mental work with boiling-point thermometers was carried 

 out on the Carnegie in 1909-10, and the results showed 

 that it would be worth while to attempt gravity work on 

 board of her. The methods and reductions hitherto 

 employed are discussed, and the view is expressed that 

 some error may attach to the results obtained by the 

 boiling-point thermometers, and that in the method of 

 reduction local gravity anomalies observed during a cruise 

 partake of the nature of accidental errors. On the 

 Carnegie it is proposed to make both shore and harbour 

 observations, especially at places where pendulum observa- 

 tions have already been made; frequent zero determina- 

 tions of the thermometers, and comparisons of the 

 barometers with shore standards, wherever available, ate 

 to be employed to determine the various errors. Tiie 

 necessary refinement of the barometric work remains a-> 

 the chief difficulty, and the hope is expressed that, in view 

 of the great importance of the subject, a method superior 

 to the present may be discovered whereby the boiling-poinf 

 thermometer may be eliminated. 



In an original memoir in the January number of Le 

 Radium, M. G. Sagnac, of Paris, shows that in order 

 that the time occupied by two beams of light in describing 

 in opposite directions the contour of an area of consider- 

 able magnitude may be the same, it is necessary and 

 sufficient if the vector which defines the relative velocity 

 of the aether with respect to the optical system is irrota- 

 tional throughout the area enclosed by the contour. In 

 order to test whether the a;ther in the immediate neigh- 

 bourhood of the earth possesses this property, M. Sagnac 

 divided a beam of light into two portions, which he sent 

 in opposite directions round a circuit consisting of a hori- 

 zontal length of about 30 metres, an equal vertical length, 

 and a third sloping one joining the two former. The two 

 beams after traversing the circuit interfere, and the bands 

 are observed in a telescope allowing a determination of 

 displacement of i/iooo of the width of a band. The plane 

 of the circuit being east and west, observations of the 

 bands were taken at various hours of the day and night, 

 but no displacements were observed equivalent to a change 

 in the relative motion of aether and matter of i millimetre 

 per second for an elevation of i metre. Any relative 



