54 



NATURE 



[April i, 1920 



gested by Sir Francis Watts, the Imperial Commis- 

 sioner of Agriculture for the West Indies, with which 

 the Committee expresses itself as in general agree- 

 ment. It includes (a) a junior course of two or three 

 years, suitable for boys leaving the Colonial secondary 

 schools and intending to follow ordinary agricultural 

 pursuits, usually in the colonies from which they 

 have come ; (b) a senior course of similar instruction 

 of not less than four years; (c) a two years' 

 course, practically the same as the last two years of 

 the previous course, for students who have already 

 undergone a training in agriculture in a university 

 or agricultural college, and thus intended to meet the 

 case of students going out from Europe to work at 

 agriculture in the tropics, whether on their own 

 account or as officials ; and {d) post-graduate study of 

 special agricultural subjects, such as mycology or 

 genetics, or the study of special crops such as sugar 

 or cacao. It is incidentally recommended that a 

 special school for the study of sugar should be estab- 

 lished. 



This is a very interesting and practical programme, 

 and it is to be hoped that it mav soon be translated 

 into reality. The only criticism that occurs to one is 

 to ask whether it is not just a trifle too ambitious for 

 a commencement and too great a change from the 

 customary methods of learning the work of tropical 

 agriculture, and whether it mav not tend to make 

 the tropical student at least, and especially him who 

 must work under seniors trained in the old wav, a 

 trifle unpractical. Great care will have to be exer- 

 cised to make the instruction as practical as possible, 

 and for this reason we note with pleasure the insist- 

 ence upon making the new college work as much as 

 possible in connection with the Imperial Department. 



Finallv, it is suggested that a fund of at least 

 .t;o,oooZ. be raised by private subscription for the estab- 

 lishment of the college, and that for maintenance 

 annual contributions be invited from the various 

 Colonial Governments, and also from the Imperial 

 Government, to which the proper development of the 

 great tropical lands of the" Empire is of such para- 

 mount importance. 



Duplex Wireless Telephony. 



A NOTHER of the interesting series of papers on 

 -^"^ wireless developments connected with the war 

 before the Wireless Section of the Institution of Elec- 

 trical Engineers was that of Capt. P. P. Eckersley, 

 read on March 17, describing experiments by Major 

 AVhiddington and himself on the application of duplex 

 wireless telephony to aircraft. The advantages of 

 "being able to converse freely and simultaneouslv both 

 ways, as is done in a true duplex system, over 

 using a change-over switch are obvious, but the elec- 

 trical difficulties in the way of its successful accom- 

 plishment are considerable. The main problem lies in 

 devising a form of circuit which will protect the re- 

 ceiver, without detriment to its efficiency, from the 

 effects of the relatively powerful high-frequency rJter- 

 nating currents generated by the transmitter. 



Two general principles have been adopted. In one, 

 two separate aerials with different frequencies for 

 transmission and reception are placed at right angles 

 and spaced more than a quarter of a wave-length 

 apart. In the other, which may employ a single 

 aerial, the "earth" connection is split, and the 

 branches are tuned so that the transmitter current 

 passes through one and the receiver current through 

 the other. Both these systems present difficulties, and 

 have been used onlv to a limited extent. A compro- 

 mise system, in which the transmitter oscillates only 

 when the operator is actually speaking, with what is 

 NO. 2631, VOL. 105] 



called a "quiescent aerial" was also experimented 

 with, but the speech was found to be much improved 

 by allowing a small permanent oscillation, increased 

 sympathetically with the voice. Such an arrangement, 

 called an "augmented oscillation transmitter," has 

 certain practical advantages, as well as incidentally 

 presenting some interesting theoretical points, but 

 forms only a "partial duplex" system, as an interrup- 

 tion during- speaking cannot be heard. The author's 

 experiments have progressed well on the way towards 

 the evolution of a practical and trustworthy system 

 of duplex wireless telephony for aircraft, and form a 

 valuable groundwork for future development. 



University and Educational Intelligence. 



Aberdeen.— At the spring graduation ceremony 

 Principal Sir George Adam Smith announced a gift of 

 2o,oooZ. from Sir Thomas Jaffrey, head of the Aber- 

 deen Savings Bank, for the establishment of a chair 

 in political economy in the University. There has 

 been a lectureship in this subject for a number of 

 years. 



The Universitv has just conferred on Sir Jagadis 

 Chandra Bose the. honorary degree of LL.D. 



Birmingham. — Mr. Arthur R. Ling, consultant in 

 applied chemistry and lecturer in brewing at the Sir 

 John Cass Institute, London, has been appointed to 

 the Adrian Brown chair of brewing. 



A bronze memorial tablet in memory of the late 

 Prof. Adrian Brown has been erected in the Brewing 

 School by past students. 



A gift has been received from the Asiatic Petroleum 

 Co. of a model drilling equipment, which will be 

 exhibited at the forthcoming Petroleum Exhibition at 

 the Crystal Palace. 



Mr. Frank Shaw has been appointed assistant lec- 

 turer in electrical engineering, and Mr. Raymond B. H. 

 Wyatt lecturer in bacteriology. 



Cambridge. — Mr. G. E. Briggs, St. John's College, 

 formerly University Frank Smart student in botany, 

 has been elected to the Allen scholarship. 



The new Statute of the University which gives the 

 degree of Ph.D. to research students in the Univer- 

 sity is the result of the work of a syndicate appointed 

 in December, 1917, "to consider the means of pro- 

 moting educational collaboration with the universities 

 of the Empire and foreign universities." The chief 

 points of interest in the proposed regulations for 

 working the Statute are as follows : — Research 

 students, who must be at least twenty-one years of 

 age on admission, must have graduated at some uni- 

 versity (Cambridge itself included), or must satisfy 

 the University as to their general educational qualifica- 

 tions. Before admission their proposed course of re- 

 search must have been approved, and they must show 

 that they are qualified to enter upon the course pro- 

 posed. Students must pursue research for three years 

 before submitting for a degree the dissertations em- 

 bodying the results of their research. Those who are 

 graduates of Cambridge need only spend one of the 

 three years at Cambridge; others must spend at least 

 two years at Cambridge. The remainder of the time 

 must be spent at some place or places of study ap- 

 proved by the University. Research students who are 

 candidates for degrees at other universities and who 

 spend at least two terms in Cambridge may receive 

 certificates of regular study and industry to cover the 

 time spent in Cambridge. A Board of Research 

 Studies is to be formed to supervise the carrying out 

 of the new scheme. The proposals show a welcome 

 movement away from the old spirit of "splendid isola- 



