528 



NATURE 



[June 24, 1920 



leafy shoots had a stellate stele, and from the en- 

 larged ends of the arms small concentric leaf-traces 

 were given off, which passed to the base of each leaf 

 but never entered the free lamina. In habit Aster- 

 oxylon agrees closely with tj)§ well-known older 

 Devonian plant, Psilophyton princeps, and to a rather 

 less extent with Psilotum. It throws light on the 

 morphology of certain Devonian plants known only 

 as impressions, and raises many questions of theoretical 

 interest which are discussed by the authors. 



New light on several problems of Arabian geo- 

 graphy has resulted from the war. In the Geo- 

 graphical Journal for June (vol. Iv., No. 6) Dr. D. G. 

 . Hogarth deals with certain discoveiies in the Hejaz. 

 It has now been found that the watershed between 

 drainage west to the Red Sea and north-east to the 

 Persian Gulf lies further east than vvas previously 

 supposed. Its exact course has still to be traced, but 

 it certainly lies some distance back from the coast 

 and runs through the Kheibar harra east of the 

 Hejaz railway. Further south in Asir it comes nearer 

 the Red Sea. Much material has been collected for 

 the mapping of the Hejaz, especially in the north, 

 against the Gulf of Akaba, and further south between 

 Wejh and Rabugh. The intervening block, except 

 for the littoral, is most imperfectly known. Con- 

 siderable additions have also been made to our know- 

 ledge of the coast-line between Akaba and Aden. Dr. 

 Hogarth concludes his paper by summarising some 

 new information about Medina, of which a Turkish 

 plan and several photographs have now been obtained. 

 A British aeroplane which flew over the city secured 

 a photograph of the railway station and immediate 

 surroundings, but strict injunctions were given not 

 to photograph the Haram or Great Mosque which 

 contains the Tomb of the Prophet. The photograph 

 secured on this occasion is reproduced, among others, 

 with the paper. 



There seems now to be evidence that so far back 

 as the beginning of the Cambrian period conditions in 

 the sea round the South Pole were not very favour- 

 able to life. In a piece of Lower Cambrian limestone 

 dredged by the Scottish Antarctic Expedition from 

 the bed of the Weddell Sea, and in other fragments of 

 the same rock from the moraine of the Beardmore 

 glacier on the opposite side of the South Pole, 

 numerous remains of the sponge-like Archaeocyathinas 

 have been found closely similar to those discovered in 

 a corresponding formation in South Australia. All 

 the Antarctic forms, however, are comparatively 

 dwarfed, and show various thickenings and irregular 

 additions to the skeleton which denote a struggle with 

 adverse conditions. The specimens are described in 

 great detail, with excellent illustrations, by Dr. W. T. 

 Gordon in the Transactions of the Royal Society of 

 Edinburgh (vol. Hi., part iv.), but they do not throw 

 any new light on the affinities of these remarkable 

 fossils. They are associated with ordinary spicules of 

 sponges, fragments of shells and trilobites, and a con- 

 siderable growth of calcareous algae. 



The Museums Journal for June welcomes the chance 

 of increased co-operation between the University and 

 the British Museum that would be afforded by the 

 NO. 2643, VOL. 105] 



new site offered to London University, but points out 

 that concentration is not altogether to the advantage 

 of students arriving from the various residential dis- 

 tricts, and that concentration in a restricted area will 

 check the inevitable expansion of both University and 

 Museum. This enforces, from another aspect, the 

 argument put forward by Sir E. Sharpey Schafer in 

 Nature for June 17. 



The advances made in wireless telegraphy and tele- 

 phony during the war were enormous, and in all the 

 three fighting Services it has established itself as 

 indispensable. A large section of the Signals experi- 

 mental establishment at Woolwich is now devoted to 

 the development of equipment to meet the requirements 

 of the Army, which differ in several respects from 

 those of the Navy or Air Force. Much of the ap- 

 paratus has to be specially compact and mobile, and 

 for the circumstances of moderq warfare the quantity 

 of messages to be dealt with in a short time renders 

 high speed of transmission essential. The adaptation 

 of the Wheatstone automatic transmitter, working 

 from a previously punched paper strip, to wireless 

 working enables speeds of transmission from 450 to 

 even 1000 words per minute to be attained. The small 

 currents through the contacts which are sufficient for 

 wireless apparatus render the conditions particularly 

 favourable for high speeds. Particular attention is 

 given to th6 linking-up of line with wireless systems. 

 High-speed messages come in over the wire in the 

 ordinary way, and are automatically handed over to 

 the wireless apparatus without loss of time in re- 

 transmission. Another recent development of wire- 

 less working, finding particularly useful application in 

 the Army, is direction-finding, and very compact sets 

 for this purpose with a range up to 250 miles are now 

 being standardised at Woolwich. A point to which 

 special experiment is being directed is the obtaining 

 of a high degree of selectivity by which extraneous 

 waves from near and far can be "tuned out " and the 

 feeblest messages of the required frequency amplified 

 to the extent necessary for satisfactory reception. 



The Deutsche Seewarte is resuming its activity in 

 the direction of publications. We have received a 

 report for the five years 1914-18, thirty-seventh to 

 forty-first year of the institution, and with it an 

 overdue report published in 19 14 of a survey voyage 

 of S.M.S. Mowe in 191 1 to the West Coast of Africa. 

 The course was from Wilhelmshaven to Ferrol, 

 Cadiz, Teneriffe, Dakar, Freetown, Lome, Lagos, 

 Lome, Accra, Lome, Duala, Banana, Boma, Swakop- 

 mund, and Liideritzbucht, the last being reached on 

 October 7, 1911. The expedition went up the Congo 

 as far as Boma. Observations were taken of the 

 depth of the sea and of the currents, temperature, 

 density, and salinity at different depths down to 

 2000 metres. This oceanography, divided into the 

 three sections, North-West, Equatorial, and South- 

 West Africa, was directed by Drs. G. Schott and 

 B. Schultz. A meteorological log was kept by Dr. P. 

 Perlewitz, including some kite observations. The 

 regular observations were taken at intervals of four 

 hours, whether in harbour or on voyage, and the ele- 

 ments tabulated, in addition to the latitude and longi- 

 tude, are direction and force of the wind, barometer. 



