September 22, 1923J 



NATURE 



457 



Scientific Exhibition at British Association Meeting. 



'T^HE ninety-first annual meeting of the British 



-*■ Association, which has just drawn to a close 



at Liverpool, was characterised by a new and im- 



fportant departure in the form of an exhibition of 



'scientific apparatus, instruments, and diagrams. The 



exhibition was on the lines of that organised each year 



in London by the Physical and Optical Societies, which 



is so effective in bringing together the users and makers 



of physical apparatus, but its scope was naturally 



wider, and many branches of pure and applied science 



were represented. 



In opening the exhibition on Monday, September lo, 

 Sir Charles Sherrington commented upon the com- 

 prehensive and representative character of the ex- 

 hibits, remarking that it was very appropriate that 

 such a collection should be brought together, and 

 that this — the first of its kind — constituted a definite 

 development in the history of the British Association. 

 He further referred to the remarkable advances in the 

 making of scientific instruments during the last three 

 hundred years, to the ever-growing importance of 

 instrumentation, and to the unavoidable complexity 

 of the apparatus needed for some of the simplest and 

 therefore the most fundamental of scientific inquiries. 

 Admission to the exhibition was not confined to 

 members of the British Association, to whom it was 

 free, but the doors were opened to any member of 

 the public on payment of the moderate sum of one 

 shilling for one day only, while three times that 

 amount guaranteed admission at any time during the 

 fortnight of the exhibition. The results for the first 

 week show that this arrangement was happily in- 

 spired, and that the exhibition was as popular with 

 the outside public as with members of the Association. 

 The number of daily tickets sold was quite naturally 

 largely in excess of the number of season tickets, but 

 the demand for the latter was quite sufficient to 

 justify their issue. 



The exhibition committee was fortunate indeed in 

 having at its disposal the excellent accommodation 

 afforded by the Central Technical Schools, Byrom 

 ^Street, and the exhibits occupied the rooms on three 

 loors of this magnificent building. The fine lecture 

 lall enabled daily lectures, in some cases illustrated 

 )y cinematograph films or experiments, to be given 

 )y men of science, a feature which contributed in no 

 Small degree to the success of the exhibition. The 

 )pularity of these lectures is sufficiently illustrated 

 >y the fact that arrangements were made for two at 

 least to be delivered a second time — " The Opto- 

 ahone," by Prof. Barr, and " Researches in Special 

 jteels," by Mr. S. A. Main (Research Department of 

 Sir Robert Hadfield's, Ltd.). Other lectures included 

 *' Ripples," by Prof. L. R. Wilberforce ; "Research 

 ind Industry," by Sir Frank Heath; "Experiments 

 )n Coal Dust Explosions in Mines," by Prof. H. B. 

 ~>ixon ; "The Compass in Navigation," by Capt. 

 >eagh-Osborne, R.N. ; "Flame," by Prof. A. 

 Jmithells : " Kodachrome Cinematograph," by Dr. 

 lees (Kodak Co., London) ; " Developments in Wire- 

 less Telegraphy," by Commander Slee (Marconi Co., 

 )ndon). 



Much attention was attracted by demonstrations, 

 iaily throughout the meeting, of the photophone 

 chibited by Prof. A. O. Rankine, and the optophone 

 (Barr and Stroud, Ltd.). In the former, the trans- 

 mitter or light modulator was installed in a room in 

 St. George's Hall, and the beam of light, fluctuating 

 in sympathy with the vibrations constituting the 

 sounds to be transmitted, was thrown across the 

 intervening space of some two hundred yards to 

 the room in the Central Technical Schools where the 



NO. 2812, VOL. I 12] 



receiving apparatus was located. The fluctuating 

 light here controlled the electric current in a selenium 

 cell, and the variable current actuated a telephone 

 receiver. In this way demonstrations were given of 

 the transmission of speech and music, and these 

 made, in particular, a wide appeal to the lay mind, a 

 result largely assisted by publicity given by the Press. 



No less popular were the demonstrations of the 

 optophone, the purpose of which is to enable the 

 blind to read ordinary printed matter. In this, a 

 selenium bridge is exposed to successions of sets of 

 light pulsations, which vary with the forms of the 

 letters passed over. Characteristic musical sounds 

 are produced in a telephone receiver by each letter, 

 constituting an alphabet readily learned. 



The exhibition committee received the support of 

 the National Physical Laboratory and of the Meteoro- 

 logical Office, Air Ministry. The exhibit of the 

 former consisted very appropriately of specimen lenses 

 for use in ships' lights, and master standards of colour 

 for testing the colour screens of ships' lights. These 

 were in accordance with the recommendations made 

 in the Report of the Departmental Committee on 

 Ships' Navigation Lights (1922), and formed an in- 

 structive display. 



The exhibit provided by the Meteorological De- 

 partment of the Air Ministry followed closely the lines 

 of demonstrations given by that department at the 

 two previous meetings of the Association, in Hull 

 and Edinburgh. A wireless receiving set was em- 

 ployed to intercept the broadcast messages forming 

 the daily international exchange of weather informa- 

 tion, and, from these, weather charts were prepared, 

 and forecasts made for the Liverpool area and the 

 Irish Sea. Visitors were, in fact, able to see in 

 miniature the complete working of a weather forecast 

 service. These demonstrations were supplemented 

 by a display of up-to-date meteorological instruments, 

 and by diagrams and photographs of geophysical in- 

 terest. Much interest was shown in the record of 

 the recent earthquake in Japan, taken at the Bidston 

 Observatory, and in a set of charts showing the pro- 

 gress of the depression which caused the destructive 

 gales of August 29-30 of this year. One of these 

 charts showed the depression completely defined over 

 the Atlantic by one of the best sets of simultaneous 

 observations from ships ever received in the IMeteoro- 

 logical Office, and the accuracy of the forecasts 

 issued on that occasion emphasises the practical im- 

 portance of such reports. 



One impression gained by a visit to the exhibition 

 was that the field covered by the exhibits was not 

 only a wide one, but also that very great care had 

 been exercised in the choice of the material shown, 

 having regard to the position of Liverpool as a great 

 seaport and its location in an industrial area. It is 

 not possible to deal in detail with the many interesting 

 and instructive things which were to be seen, com- 

 prising, as they did, many striking exhibits in wireless 

 transmission, in the manufacture of steel, in optical and 

 electrical instruments, in instruments employed in navi- 

 gation, including the gyro-compass, in the chemical and 

 dye industries, in the manufacture of glass, in chemical 

 apparatus, in recorders for use in the control of fuel 

 combustion, in photography and photomicrography, 

 in meteorological instruments, and in other branches 

 of science and industry. Among the instruments 

 which attracted special attention was K. C. Cox's 

 selenium magnifier (H. W. Sullivan, Ltd.), which 

 was shown working in connexion with a syphon re- 

 corder for long-distance submarine cable signalling, 

 and is capable of giving magnification up to ten 



