June 24, 1922] 



NATURE 



819 



Wireless Telephone Receiving Sets. 



A NUMBER of patterns of complete wireless tele- 

 ■i *■ phone receiving sets are being introduced to meet 

 the requirements of the popular broadcasting services 

 which will shortly be put in operation. It is regrettable 

 that there has been a tendency, in striving after 

 simplicity and cheapness, to cut the apparatus dowTi 

 to rather fine limits, resulting in the elimination of 

 adjustments and features which are most desirable 

 for really satisfactory working. Indeed many of the 

 sets being advertised are little better than toys. It 

 is true that reception of a sort is quite possible with 

 elementary crystal sets, but the unskilled user will 

 undoubtedly be better served by the slightly more 

 expensive valve apparatus which is now being made in 

 simple and convenient forms. 



We have had the opportunity of inspecting an equip- 

 ment supplied by the firm of Radio Supplies (236 High 

 Holborn, W.C.i) which is typical of a good class of 

 apparatus of this sort. This firm's M type set, which 

 is sufficient for all ordinary reception, is of the two- 

 valve pattern, one valve acting as detector and the 

 other as amplifier, the latter being in the low-frequency 

 circuit, forming what is termed a note-amplifier. The 

 valves with their filament rheostats, switches, 

 terminals, etc., are mounted on a compact case, 

 but the aerial inductance is carried on a separate 

 stand. In this the convenient arrangement is adapted 

 of obtaining a variable coupling by turning a simple 

 milled head, which alters the relative angular position 

 of the coils in question. Alternative coils, which 



can easily be plugged into place on the swinging arm, 

 are used for different " bands " of wave-lengths. The 

 fine tuning adjustment is obtained by a very compactly 

 arranged variable condenser, and by this means the 

 apparatus can be tuned to any wave-length from 180 

 to 30,000 metres. 



With the pattern of valve employed a six- volt 

 accumulator is generally used for the filament circuits, 

 and it is recommended that this be of the 60 ampere- 

 hour size, if the apparatus is in daily use for 

 long periods, as then it will not have to be charged 

 more than about once a week. It is, of course, possible 

 in places where there are absolutely no facilities for 

 recharging accumulator cells, to use large dry cells 

 for the filaments. The high-voltage or anode circuits 

 of the valves are supplied by compact multicell dry 

 batteries at voltages from 30 to 70 volts according to 

 circumstances. These are made up in blocks about 

 8 inches long of 30 cells each, and in view of the very 

 small current taken from them, should last nine 

 months without renewal. 



, A set of this kind, which complete with a small 

 aerial and every accessory would cost from 25/. to 30Z., 

 will pick up in addition to telephony, spark, tonic 

 train, or continuous wave signals. Even with an indoor 

 " aerial," the concerts from the Hague are audible 

 all over the room, with an ordinary telephone receiver. 

 The firm also supply larger sets with further degrees 

 of amplification, but for all ordinary work two valves 

 are quite sufficient. 



Obituary. 



Prof. A. Laveran, For. Mem., R.S. 



FRANCE lost one of her great men of science when 

 Charles Louis Alfonse Laveran died on May 18 

 at the ripe age of seventy-six. His death, following 

 so closely on that of Sir Patrick Manson, may be said 

 • to close one chapter in the history of malaria, the 

 important preliminary chapter which paved the way 

 for the brilliant and far-reaching researches of Ross 

 and the Italian observers. 



Laveran was bom at Paris on June 18, 1845, his 

 father, a military surgeon, being a professor at the 

 school of Val-de-Grace. The son followed in his 

 father's footsteps, for, after completing his studies in 

 Paris, he decided to become an army doctor, and 

 matriculated as a medical student at Strasbourg. He 

 graduated in 1867, submitting a thesis on the regenera- 

 tion of nerves. In 1874 he joined the staff of the 

 Val-de-Grace School of Military Medicine, and in 1878 

 was sent to Algeria, where he remained till 1883. It 

 was in this country, at Bone and at.Constantine, that 

 he turned his attention to malaria, and carried out the 

 f memorable work with which his name will for ever be 

 associated. 



As a result of his labours Laveran was appointed, 

 in 1884, professor of military hygiene and clinical 

 medicine at Val-de-Grace, posts which he held for ten 

 years. Thereafter, for a short space, he was concerned 



NO. 2747, VOL. 109] 



with administrative medical and sanitary work at 

 Lille and at Nantes, but his heart was given to scientific 

 pursuits, and, desirous of continuing his researches, 

 more especially in protozoology, he relinquished his 

 appointments in 1897, and retired with the rank of 

 medecin principal of the first class. 



Laveran then entered the Pasteur Institute where 

 he soon became a professor. There he remained for 

 the rest of his life, always busy, a tireless investigator 

 who never flagged until age and infirmities conquered 

 even his indomitable spirit, and he was no longer able 

 to use his beloved microscope and pursue those studies 

 to which he had devoted his life to such good purpose. 

 As Prof. Brumpt pointed out in his address to the 

 Academy of Medicine, a failure in Laveran's powers 

 was noticeable after the fetes in connection with the 

 centenary of that Institution in which he took an active 

 part. The effort exhausted him, and he no longer 

 attended the meetings of scientific societies with his 

 wonted regularity, a sure sign in his case of the approach- 

 ing end. 



Laveran's greatest work, and that which entitles 

 him to a place in the medical Valhalla, was his dis- 

 covery of the parasite of malaria. In Algiers he com- 

 menced his studies on the pathology of that disease, 

 and his attention was specially directed to the char- 

 acteristic pigmentation of the liver and brain in fatal 

 cases. This had already b^en recognised, but it was 



