June 25, 1896] 



NA TURE 



187 



The desire of every lad lo make something is gratified and 

 educationally directed in the Engineering Workshop, which is 

 liberally fitted with milling, planing, shaping, and slotting 

 machines, and four of the lathes, we were told, had been made 

 by the students themselves, while one weighing three tons, and 

 having a lo-foot gap bed, we saw in process of construction. 



The economy of a De Lavel steam turbine, running at 32,000 

 revolutions a minute, and of a Tower spherical engine, were 

 being tested in the Steam Laboratory, while a 40-horse power 

 condensing engine, specially designed to illustrate the eftect of 

 varying the conditions of working, has fitted to it a very satis- 

 factory hand-brake, indicator gear, • and arrangements for 

 measuring the circulating water, the condensed steam, the 

 jacket and receiver drainage, &c. And, as a memento of the 

 improvements that can be effected in prime movers by experi- 

 mental inquiry, there stands the very engine used by the late 

 Mr. Willans in his classical investigations on steam engine 

 economy, cut through so as to expose a sectional view of the 

 cylinders, pistons, and valves. 



Adjoining the Steam Laboratory is the boiler-room, where in 

 addition to the Lancashire and Cornish boilers, used for 

 generating steam for the engines, is a Babcock and Wilcox boiler, 

 use;! exclusively for boiler and fuel tests, with its accompani- 

 ments of feed-water measuring tanks, coal-weighing apparatus, 

 dasymeter for determining the percentage of carbonic acid in 

 the furnace gases, &c. 



In the laboratories of the Physical Department are many 

 instruments and pieces of apparatus that have been developed 

 there, and specimens of which are now to be found in other 

 colleges, electrical works, and electric lighting stations. In the 

 dynamo room are speed cones by means of which the speed of 

 any dynamo can be varied between wide limits, and, what is 

 equally important for experimental purposes, can be kept at a 

 constant value independently of variations in the speed of the 

 engine, or in the amount of slip of a belt when it is transmitting 

 different ainounts of power. Doubts were originally expressed 

 as to the possibility of such cones being used to transmit even 

 lo-horse power satisfactorily, but their successful working 

 having been jiroved, sets of them were reproduced for 

 University College, Nottingham, the McGill University, 

 Montreal, &c. This room contains many different types of 

 dynamos, and, as space is limited, one is driven with a weighted 

 pulley hanging in a very short belt passing over the fly-wheel of 

 the engine, the dynamo itself being balanced on trunions, so 

 that it turns on an axis at right angles to that round which the 

 armature rotates. 



The " injector " for producing any desired shape of wave, and 

 so enabling one alternating current dynamo to serve the purpose 

 of many, was shown in use, and the vibrating wire curve tracer, 

 descril)ed at the last meeting of the British Association, was 

 writing out the wave-forms so produced. The permeability of 

 iron rods was being examined with the small dynamo recently 

 shown at the Royal Society's soiree, and the regulation of trans- 

 formers differentially tested with an electrostatic voltmeter, with 

 which a pressure of one volt can be measured without any 

 independent electrification. 



Those interested in the bills sent in by Electric Light Com- 

 panies had an opportunity of seeing American, English, French 

 and German electric supply meters being tested at various tem- 

 peratures in the Magnetic Research Laboratory, as well as ex- 

 jieriments on the slow rise of temperature in underground electric 

 mains. 



The Electrical Research Laboratories contain various forms of 

 electrostatic voltmeters, some of which were being tried, while 

 others were in use for measuring the electric pressure at which 

 cables and insulating oils break down by sparking. A Lorenz 

 apparatus for the determination of the ohm, which had been 

 constructed regardless of cost for the M'C.ill University, and sent 

 to the college to be tested, attracted much attention. It is cer- 

 tainly unique in its details, and eminently characteristic of the 

 transatlantic millionaire who stipulates that the wealth which 

 he showers on the laboratory named alter him shall be used to 

 purcha.se only the " very best apparatus." How many an 

 English profes.sor would delight in having such a condition im- 

 posed by a benefactor determined that the laboratory founded by 

 him should be the most costly in the world. 



In another room was a secohmmeter spinning out coefficients of 

 self-induction, a new addition to the Wheatstone's bridge for 

 facilitating the measurement of very small resistances, and an 

 artificial submarine cable, electrically as I'jng as those under the 



Atlantic, with which the retardation in the passage of the tele- 

 graphic signals was demonstrated to the visitors. 



In the Arc Lamp Laboratories the photometry of the arc, and 

 the steady feeding of the carbons with various types of lamps, 

 were shown, also the details of the experimental lamp used in the 

 recently published researches was explained. The observer 

 sees close to him the arc itself and its image enlarged ten times, 

 also the spots of light indicating the current flowing and the 

 potential difference maintained between the carbons ; while in 

 front of him are handles for regulating the current, the position 

 of each carbon, &c. Mark Tapley would doubtless have said 

 that there was no credit in making discoveries under such 

 circumstances. 



On a screen on a wall the voltmeter and ammeter spots of 

 another arc were seen dancing up and down, and proving that 

 when an alternating current is superimposed on a direct current 

 arc the oscillations of potential difference and current are in the 

 same direction when the carbons are cored, but in opposite 

 directions when they are solid. 



Gas-burners and glow-lamp testing, polarimetr)-, and spectro- 

 photometry are carried out in the Senior Optical Laboratory, 

 and the curves of results obtained by the students showed the 

 most economical gas pressure to use with each type of burner ; 

 why it pays the gas companies to make the gas flare and the 

 private consumer to use governed burners,' and how much 

 dearer, as far as mere light is concerned, is glow-lamp lighting 

 than gas lighting with the Welsbach burners. 



A range of rooms on the first floor is devoted to the Junior 

 Physical Laboratories, and in them students, who frequently 

 have never worked in a laboratory before, learn the principles 

 of electricity, heat, light, magnetism and sound by performing 

 an organised series of quantitative physical exercises. 



In both the Physical and Chemical Departments there were 

 several exhibits of "seeing with X-rays," the potassium-platino 

 cyanide screens, which have been so successfully constructed by 

 Mr. Jackson, being lent for the occasion. The majority of the 

 exhibits, however, in the Chemical Department were connected 

 with the educational methods employed, and with the results 

 which have been obtained from the researches carried out by 

 the advanced students and the staff. Prof. Armstrong has long, 

 advocated that every student of chemistry should be early infused, 

 with the spirit of scientific inquiry ; and that this principle has 

 been practised in his laboratories, and not merely preached in 

 his lecture-room, was proved by the large number of specimens 

 of new series of compounds which were exhibited as the out- 

 come of the work in his department. Sulphuric derivatives of 

 camphor prepared for the first time in a pure state, hundreds of 

 specimens of derivatives of naphthalene — the hydrocarbon from 

 which so many modern dye-stuffs are made— obtained experi- 

 mentally, and the apparatus for many researches in course of 

 progress, attracted attention. 



In the Junior Chemical Laboratory were exhibited the 

 apparatus and experiments used in connection with the courses 

 to teachers that have been given at the College. This apparatus 

 is suitable for the use of teachers giving elementary instruction 

 in technical schools, as well as for carrying out the experiments 

 recommended in the syllabus of elementary science (chemistry 

 and physics) issued by the Incorporated Association of Head- 

 masters. 



For the last ten years Dr. Armstrong has made strenuous 

 efforts to obtain adequate recognition for that hitherto much 

 neglected, but all important branch of physical chemistry, 

 crystallography, and in consequence the crystallographic branch 

 of the department has gradually extended in size, until at present 

 the laboratory devoted to that subject rivals the best on the 

 continent for completeness of equipment. Numerous measure- 

 ments and drawings of crystals that had been made by the 

 students were exhibited, and demonstrations of the methods 

 employed in the optical examination of crystals were given in 

 the adjoining lecture theatre during the evening, apparatus that 

 had been specially devised lo facilitate the accurate examination 

 of doubly refracting substances being employed for the purpose. 

 In the Woodcarving Department, under the direction of 

 Miss Rowe, there was an exhibition of carving in a variety of 

 styles by present and past students, some of the latter being now 

 the instructors in this and in other schools of art woodcarving. 

 A renaissance panel illustrative of the arts of sculpture, archi- 

 tecture, and literature, an Italian bracket, and a pediment for a 

 bookcase, a low relief renaissance frieze, &c., showed boldness 

 and finish, while the practical demonstrations of the different 



NO. 1 39 1, VOL. 54] 



