5S6 



NATURE 



[October 13, 1904 



the method they had adopted for measuring by a watt 

 meter the total losses due both to hysteresis and eddy 

 currents. 



Dr. W. E. Sumpner and Mr. R. W. Weekes, in a paper 

 on the Hopkinson test as applied to induction motors, stated 

 that they had found Dr. Hopkinson 's well known method, 

 with certain modifications, so satisfactory in testing induc- 

 tion motors that they considered it was desirable to direct 

 attention to the experimental details and to give particulars 

 of the arrangements of the machines and the instruments 

 needed for the test, and of their methods of determining 

 the belt losses. In an appendi.x the results obtained in 

 testing three-phase motors by this method were given. 



Dr. W. .M. Thornton contributed a paper on distribution 

 of magnetic induction in multipolar armatures. The object 

 of this paper was to discuss the best methods for deter- 

 mining the most suitable radial depth of an armature core 

 for either continuous or alternating machines. 



The last two papers dealt with on August 22 had reference 

 to standards of light. Prof. J. A. Fleming, in his paper 

 entitled " Large Bulb Incandescent Electric Lamps as 

 Secondary Standards of Light," described a method he had 

 devised of using as a secondary standard of light an in- 

 candescent filament fixed in a large bulb about 12 centi- 

 metres in diameter and about 20 centimetres long. The 

 use of this large bulb diminished considerably the deposit 

 of carbon upon the interior of the glass, and therefore the 

 rapid falling off of candle-power with age of the lamp. He 

 had found such lamps very suitable for photometric pur- 

 poses. His method of employing them was equivalent to 

 the well known system of double weighing. One of these 

 standard lamps was balanced in the photometric gallery 

 by an ordinary incandescent lamp, and then the standard 

 lamp was removed and the lamp the candle-power of which 

 it was desired to determine was substituted for it. and 

 moved in or out towards the photometer disc until it also 

 balanced the ordinary incandescent lamp previously used 

 against the standard lamp. The second of the two papers 

 was by Mr. ClifTord Paterson, and was entiled " Some 

 Investigations on the Ten Candle-power Harcourt Pentane 

 Lamp made at the National Physical Laboratory." The 

 author has been carrying out an investigation at the National 

 Physical Laboratory on the effect of changes in the baro- 

 metric pressure and of moisture in the atmosphere on the 

 flame standard, and the work is still going on. 



On Tuesday, August 23, the first business was the read- 

 ing of the report of the Committee on the Mersey Tidal 

 Regime. Briefly the committee has found that though 

 extensive dredging has now been carried on in the Mersey 

 for such a long period of time, the regime of the tides has 

 hardly been altered. 



Major Sir Hanbury Brown then read a most interesting 

 communication on the control of the Nile, the paper being 

 fully illustrated with lantern slides. The author described 

 the whole of the engineering works which have been con- 

 structed for the purpose of increasing the area of irrigation 

 in Egypt since the days of .'\rabi Pasha's abortive revolu- 

 tion. Two great schemes have now been completed, first, 

 the reconstruction of the old delta barrage so that it now 

 can be completely utilised for its original purpose and a 

 head of 20 feet of viater can be held up, and, secondly, the 

 construction of the great Assuan dam and Assiut barrage. 

 The wonderful increase in the industrial prosperity of Egypt 

 which has been brought about by these great engineering 

 works reads almost like a fairy-tale, and not the least 

 important of the social advantages has been the abolition 

 of forced labour or corvee. In the discussion. Sir Colin 

 .Seott-Moncrieff, who has been responsible for so much of 

 this splendid work, told an amusing story of how, during 

 the reconstruction of the great delta barrage, the last hole, 

 which had almost baffled the engineer, was at length closed 

 by the use of costly curtains taken from an unused Khedivial 

 palace standing near the barrage. 



Mr. J. H. Wicksteed's paper on a universal testing 

 machine of 300 tons for full sized members of structures 

 described the machine made for the French Government by 

 his firm, Messrs. Buckton and Co., of Leeds, which was 

 officially inaugurated at the Conservatoire Nationale des 

 .Arts et Metiers on June 16 of this year. This formidable 

 machine will take in columns or tension bars 88 feet long 

 by 3 feet 3 inches by 3 feet 3 inches, and it will admit beams 



NO. 1S24, VOL. 70] 



3 feet 3 inches broad by o feet 6 inches deep on a 20 fee« 

 span, and can be changed from one form of test to another 

 with great rapidity. On the day of the inauguration, a 

 steel tension bar was broken under a load of 228 tons, and 

 immediately afterwards a thick slab of armoured concrete 

 was broken on a span of 16 feet 6 inches. 



Prof. J. O. .'\rnold then read a paper on the fracture of 

 structural steel under alternating stresses, in which he de- 

 scribed a method he had devised and the special machine 

 he had invented for placing test specimens under severe 

 alternating stresses slightly beyond the elastic limit; his 

 method, as it were, carried out the Wohler tests in two or 

 three minutes. Though the investigation was still going 

 on, the author stated that the results obtained so far con- 

 vinced him that the micrographic methods of examining 

 steel had in their turn failed to show the cause and preven- 

 tion of sudden rupture under vibration and alternation of 

 stress. 



The last two papers on August 23 were contributed by 

 Mr. R. A. Hadfield. The first was on the production of 

 magnetic alloys from non-magnetic metals. In it he 

 stated that Dr. Heusler had produced a magnetic alloy of 

 copper, aluminium, and manganese, and that the magnetic 

 properties of this alloy were to be attributed entirely to the 

 presence of the manganese. Mr. Hadfield himself had 

 made the alloy, and was still carrying on an investigation 

 in reference to it. The alloy was very brittle, and could 

 not be forged either cold or hot. The second paper, on ex- 

 periments relating to the effect upon the mechanical proper- 

 ties of iron and alloys of iron produced at liquid air tempera- 

 tures, gave a brief account of some interesting experiments 

 on the effect upon pure iron of great cold. Much fuller 

 details of this investigation are to be given at the forth- 

 coming meeting of the Iron and Steel Institute. 



On Wednesday, August 24, the last day of the meeting, 

 several papers of interest were taken, the first being a paper 

 by Mr. Horace Darwin and Mr. C. V. Burton on side-slip 

 in motor cars. The results which had been obtained by 

 the authors in their investigations into this question were 

 illustrated by a small model car, which ran down an inclined 

 plane. The authors were of opinion from these experiments 

 that side-slip would be considerably reduced by steering with 

 the hind wheels and driving with the front wheels, though 

 this car would not be so convenient for steering as the 

 ordinary car. 



Prof. Ernest Wilson gave a further account of his experi- 

 ments on the electrical conductivity of certain aluminium 

 alloys as affected by exposure to London atmosphere. The 

 author has recently been employing micrographic methods 

 in his investigations. He was of opinion that the great 

 difference which existed between the tensile strengths and 

 the other qualities of these alloys was not due to variation 

 in structure. 



Mr. J. Casey then described the proposed barrage of the 

 River Thames, and two brief papers, one on the testing of 

 alternating current motors by continuous current, by Mr. 

 Wm. Cramp, and the other on the action of lightning 

 strokes on buildings, by Mr. Killingworth Hedges, brought 

 the proceedings of this section to a close. 



It is pleasant to record that the attendance at Section G 

 at Cambridge was considerably above the average, and 

 this was all the more gratifying inasmuch as several of 

 the papers contributed were of unusual importance and of 

 high scientific value. T. H. B. 



PHYSIOLOGY AT THE BRITISH 

 ASSOCIATION. 

 T"HE president, Prof. C. S. Sherrington, F.R.S., de- 

 livered an address on the morning of August 18, 

 choosing for his subject the " Correlation of Refie.xes and 

 the Principle of the Common Path." This address has 

 already appeared in Nature (.September 8). 



Prof. J. A. MacWilliam read a paper on reflex and direct 

 muscular response to galvanic currents in fishes. His ex- 

 periments had proved that eels were remarkably responsive 

 to electrical currents, a responsive fin movement of a reflex 

 nature being readily elicited. The negative pole was usually 

 the effective one. Frogs, newts, carp, &c., gave negative 

 results. After death of the spinal cord much stronger 



