47o 



NATURE 



[October 5, 191 1 



dealt very largely with the question of the effects of the 

 combinations of the natural oscillations of a vessel with 

 the forced oscillations produced by wave systems, which in 

 general produce their most dangerous effects before a per- 

 manent rigime is established. In spite of the labours of 

 previous investigators, the magnitudes of the oscillations 

 produced in this transition period under various conditions 

 are still to a large extent unknown; and Prof. Biles was 

 able _ to indicate the methods of the investigation he is 

 making for solving these problems experimentallv, but 

 owing to an unfortunate illness these were not completed 

 in time for the meeting. 



The important paper on the corrugation of tramway 

 rails, which was brought before the section bv Mr. Worby 

 Beaumont immediately after the president's address, gave 

 an interesting account of the phenomena observed on rails 

 in service, and also particulars of an experimental investi- 

 gation by the author on the contact areas between loaded 

 wheels and rails, which enable conclusions to be drawn 

 as to the intensities of the compressions and tensions pro- 

 duced by wheels rolling on rails of differing degrees of 

 hardness. In the discussion which followed, Mr. Alexander 

 Siemens suggested the use of hard metal for the sides of 

 the rail with a softer metal composing the head ; he con- 

 sidered that a reduction of speed and weight, and the use 

 of larger wheels, such as the author suggested, were 

 impossible under modern conditions. Sir William White 

 gave particulars of the wear of rollers due to gun fire in 

 turrets, and could not agree with Mr. Siemens 's suggestion 

 of a composite rail, while in replv the author defended his 

 proposals. The proceedings on Thursday concluded with a 

 paper on the Anschutz gyro-compass by Mr. Elphinstone, 

 accompanied by a demonstration on a machine which was 

 on view during the remainder of the meeting. 



This instrument depends for its action on the precession 

 effect of a rapidly rotating wheel due to the influence of 

 gravity and its movement over the surface of the earth, 

 and this effect is utilised for the purpose of a compass by 

 employing a gyroscope running at 20,000 revolutions per 

 minute, and floating in a mercury bath. The precession 

 effect tends to cause the axis of the rotating mass to lie 

 in the plane of the meridian, and hence true north is 

 obtained. Unfortunately, time did not permit of a dis- 

 cussion on this paper. 



The first paper at Friday's meeting of the association 

 dealt with the question of electric drives for screw pro- 

 pellers, and Mr. Mavor advocated the use of steam turbines 

 or internal-combustion engines running at a high speed and 

 coupled to a generator. The current so obtained is used 

 to drive a motor on a slow-speed propeller shaft, and the 

 author claimed for this arrangement a high efficiency of 

 power-generating plant and propeller, with an increased 

 flexibility in the system, which offered great advantages 

 and increased economies bevond those given bv existing 



IZrn™ ', n ,„? lany kinds of vesseIs - The President. Sir 

 William White, Prof. Dalbv, and others took part in a 

 detailed technical discussion, in which the progress in the 

 design of electric generators and propellers fo'r ships and 

 the uses of the author's system were clearly indicated. 



A second paper on electrical steering, "bv Mr. Haigh, 

 described an arrangement of a constantly running motor 

 operating the steering gear bv magnetic "face clutches, an 

 arrangement which allows of an extremely sensitive regula 

 tion of the rudder with great economv of" power, since the 

 motor may, if required, be run from the lighting circuit 

 of the ship. Sir William While in opening the discussion 

 said that he viewed electrically operated steering gears 

 with much favour. The sensitiveness of the control was 

 remarkable, almost too much so for the ordinary quarter- 

 ed who would never lei the helm alone, although this 

 1 had no real value in keeping the 

 v " ss "' '" hei course : as a consi quence, it had been 'found 

 ;ary to provide hunting gear to diminish the sensitive- 

 " ess "' electric steering gears. Mr. Hawksley pointed out 

 lv. u y 1, necessary it was still to provide iusiharv htnd 

 geai for emergencies. 



next pap.,, by Mr. T. F. Wall, on the repulsion 



motor. u..s essentially mathematical, and after a shorl 



'^J, 1 '""" <"""' il by Mr. Haigh, Captain Sankey and Mr. 



,"" :! " ' p pi or, a study ol human suscepti- 



vibration by aid of an instrument consisting 



NO. 2TS8. VOL. 8?] 



essentially of a small mirror centred on a fine spindle and 

 floating in a mercury bath. When the mercury is set in 

 vibration by any disturbance, it causes the mirror to- 

 oscillate and throw a spot of light on a screen. The 

 authors pointed out that the effects of vibration on in- 

 dividuals depend to a large extent on the frequency as well 

 as on the amplitude, and that the perceptive faculty is very 

 and often untrustworthy, points also emphasised 

 by Sir William White and Prof. Petavel, the latter point- 

 ing out that the association of sound and mechanical vibra- 

 tion had in general a very disturbing effect on individuals. 



A paper on some new aluminium alloys, by Prof. Wilson, 

 concluded Friday's proceedings, and in the absence of the- 

 author was taken as read. 



The section, which met again on Monday, devoted a 

 couple of hours to a joint discussion on aeronautics with 

 Section A, of which an account has been given already, 

 and on its conclusion Prof. Howe gave a very striking 

 demonstration of the recent developments in wireless tele- 

 graphy by aid of an aerial running from the top of the 

 Town Hall into the lecture-room. With the aid of a 

 Brown telephonic relay the audience was able to follow the 

 time signals sent out from Wilhelmshaven, and to dis- 

 tinguish these from signals from other stations like that 

 on the Eiffel Tower. In his paper the author dealt very 

 fully with the improvements which have been made to 

 prevent interference, and in a succeeding paper Captain 

 Sankey described a portable wireless plant of the Marconi 

 Company adapted for carriage on horseback, and capable 

 of erection in a few minutes for use up to 100 miles. A 

 short discussion by Profs. Dalby and Howe and Mr. 

 Kilburn Scott concluded the day's proceedings. 



On Tuesday three papers dealing with some modern 

 methods of generating power were grouped together for 

 discussion. Mr. Marshall described the special features and 

 merits of the superheated over-type steam engine, Mr. 

 Tookey gave a careful analysis of the costs of power pro- 

 duction with suction gas engines, and Mr. Day gave a 

 similar analysis for Diesel engines. The long and detailed 

 discussion which followed was of the greatest interest, and 

 was prolonged much beyond the time originally fixed for 

 its termination. Mr. Rosenthal, who followed with a paper 

 on marine oil engines, dealt with the most recent develop- 

 ments in this important subject ; and the discussion, in 

 which the president, Sir William White, Mr. Day, and 

 Mr. Rosenthal joined, was chiefly remarkable in showing 

 how confident these authorities are in the continuance of 

 the supremacy of the steam turbine in naval work for many 

 years to come 



An overflow meeting on Wednesday was devoted to three 

 papers of a more general nature and of great interest. 



Mr. Kilburn Scott described the manufacture of nitrogen 

 products by electric power, and particularly emphasised the 

 importance he attached to this country's possessing the 

 means for manufacturing all the nitrogen compounds re- 

 quired for explosives, and the danger of depending on 

 foreign supplies in times of war. Sir William Ramsay 

 agreed with the author that it was most desirable to locate 

 factories in the neighbourhood of coal mines, and Sir 

 William White expressed his general agreement with the 

 author's views, although he did not consider that the pre- 

 sent impossibility of manufacturing all the essential con- 

 stituents of explosives in this country was a national danger. 

 Prof. Petavel discussed the efficiency of the electric process, 

 anil Mr. Wimperis suggested the utilisation of the waste 

 gases from Mast furnaces for the process, and estimated 

 the power available. In the following paper, on smoke 

 abatement, by Dr. J. S. Owens, the fixing of a new 

 standard of smoke emission from factory chimneys was 

 suggested, .mil an instrument for measuring smoke density 

 was exhibited. After a spirited discussion the final paper 

 of the section was read by Mr. Yorath Lewis, on a new 

 system of continuous transportation for passenger and othi 1 

 train services 



The distinctive feature of tie system is an endless screw 

 of variable pitch, which enables the speed of passenger 

 carriages to be varied at will, while the energy now lost I 

 in stopping trains by brakes is given back to the screw 

 during the retardation, thereby avoiding a large waste of 

 power when stations are frequent. The author enumerated 

 many other advantages of his system, among which were 



