53° 



NATURE 



[October 19, ign 



THE SCIENCE SECTION OF THE TURIN 

 INTERNATIONAL EXHIBITION. 



\\MIEX the scope of the Franco-British Exhibition was 

 ' under consideration, the British Science Guild 



approached the organisers and suggested that a science 

 section should be arranged. The suggestion was agreed 

 to ; and it will be remembered how successful the exhibit 

 was, and what a large amount of interest it aroused. 

 Since then similar exhibits have been arranged at the 

 Japan-British Exhibition and the present Coronation 

 Exhibition, and still continue to attract attention. 



The Exhibitions Branch of the Board of Trade has, at 

 the instance of the Physical Instruments and the Chemical 

 Committees of the Royal Commission appointed to deal 

 with the exhibitions at Brussels, Rome, and Turin, 

 organised an exhibit on somewhat similar lines. It was 

 realised that at international and other exhibitions physical 

 and chemical instruments and apparatus are not shown to 

 advantage. The facilities for examination of the instru- 

 ments are inadequate, owing to the fact that they are 

 usually shut up in cases. Generally speaking, also, there 

 is no one there to take them out and explain them to those 

 who may be interested. It was therefore decided to instal 

 working chemical and physical laboratories, in which 

 exhibitors would have, for the first 

 time in international exhibitions, an 

 opportunity of having their instruments 

 explained and demonstrated. The 

 educational value of such a system of 

 exhibiting is obvious, not only from the 

 point of view of the manufacturers, but 

 also to the public. The average person 

 has no idea of what goes on in a 

 l.liysical or chemical laboratory, or 

 vhat the apparatus, generally seen in a 

 rase, is employed for. In these labora- 

 tories actual experimental work can be 

 seen in operation, and the demon- 

 strators are there to give explanations 

 to those seeking information. It should 

 be mentioned here that professors and 

 students from the universities and poly- 

 technics on the Continent have taken 

 great interest in the laboratories, in 

 many cases spending several hours, and 

 coming not once, but several times. 



A Joint Committee of Mathematical 

 and Scientific Instruments and Chemical 

 Industries Committees was appointed 

 to deal with the matter and to appoint 

 competent scientific representatives to 

 act as demonstrators in the labora- 

 tories. 



The laboratory fittings were con- 

 structed by Messrs. Baird and Tatlock, 

 Ltd., under the directions of the joint 

 committee and personal supervision of Dr. F 

 Perkin. 



In the physical laboratory a dark-room has been set 

 apart, where demonstrations are given with the well-known 

 optical lantern of Messrs. Reynolds and Branson. The 

 lantern employed is a special one fitted with a movable 

 stage, so that it can be used for ordinary optical work and 

 for illustrating practical experiments in science teaching. 

 It is also fitted with a polariser, which, by moving the 

 stage, can be brought into position, and by a further move- 

 ment of the stage a microscope of special design can be 

 used. Thus bacteriological, physiological, and natural- 

 history specimens can be shown. 



On the bench adjoining the dark-room Messrs. Reynolds 

 and Branson exhibit other types of lanterns, and the Barr 

 and Stroud lantern-slide apparatus. This very convenient 

 piece of apparatus is fitted with graduated scales, which 

 enable the operator without calculations or focussing on 

 the screen, rapidly to prepare a lantern-slide. 



Beyond this is an interesting exhibit by Robert Paul of 

 el ctriral apparatus, including the Irwin oscillograph, on 

 which are shown both the current and pressure curves 

 of the alternating current, supplipd by a small alternator 



NO. 2190. VOL. 87] 



of the Crypto Electrical Company, and complete appar- 

 atus for making measurements of self-induction by 

 means of the Campbell variable mutual inductance, the 

 alternating current being obtained by a microphone 

 hummer. 



On the next bench Messrs. J. J. Griffin and Sons show 

 Sand's apparatus for the electro-deposition of metals, and 

 their separation by means of an auxiliary electrode, the 

 potentiometer box containing a capillary electrometer of 

 special design. On the opposite bench Messrs. Townson 

 and Mercer exhibit apparatus for the demonstration of the 

 laws of mechanics, and also certain laboratory electrical 

 instruments. 



Messrs. Adam Hilger show their wave-length spectro- 

 scope. Other apparatus on this bench consists of a collec- 

 tion of electrical and magnetic testing instruments by 

 Messrs. Baird and Tatlock, Negretti and Zambra, the 

 well-known " Tintometer " for colour estimation, two 

 mathematical models in plaster by Prof. Crum Brown, 

 F.R.S., and a " Geryk " vacuum pump by the Pulsometer 

 Engineering Co., Ltd. 



On a separate bench Messrs. T. Oertling have a splendid 

 collection of assay and chemical balances and accessories. 



The central bench contains some interesting examples 

 of modern electrical instruments made by the Cambridge 



Mollwo 



Fig. i.— General View of Chemical Laboratory. 



Scientific Instrument Company, amongst which are the 

 " Duddell " oscillograph, with camera outfit, for use on 

 circuits up to 50,000 volts, shown in operation ; a 

 " Callendar " recorder connected to an open-wound 

 thermometer, by means of which a continuous record of 

 the laboratory air temperature is obtained ; the 

 " Thread " recorder, connected to a copper couple, 

 arranged so that its extreme sensibility can be shown ; a 

 laboratory type pyrometer with a platinum platinum- 

 iridium couple (this is used for showing the temperature of 

 an electrically heated laboratory furnace). 



Most of the firms showing in the laboratory also have 

 good exhibits in the Physical Instruments Court. 



On entering the chemical laboratory, the first bench on 

 the left-hand side is a furnace bench of Yorkshire stone 

 with a uralite hood. On this bench various furnaces by 

 Messrs. Fletcher Russell and Co., Ltd., are exhibited, 

 such as are employed in metallurgical and assay work ; 

 also laboratory burners of various design. 



On the opposite side is a bench which is in part fitted 

 up for electrochemical analysis, and here actual analytical 

 operations are from time to time carried out by the labora- 

 tory demonstrator. On another part of the same bench 



