394 SECTIONAL TRANSACTIONS.— G. 



water into the vessel is kept constant, as is the electric current which charges 

 the condenser used in the time base, and the ' grid bias ' of the thyratron 

 is represented by a pivoted arm which prevents the tilting over of the vessel 

 until it has filled to a definite level. The height to which the vessel must 

 fill before tilting over is controlled by a weight on the pivoted arm. Refer- 

 ence is also made to the vibrations used in one form of camera. The 



Be 



angular velocity of a free electron rotating in a magnetic field is equal to — 



Ttl , 



where B is the strength of the field and e and m are the charge and mass 

 respectively of the electron, and is independent of its initial speed. The 

 arrangements for focussing the photo-electric image so as to produce the 

 necessary photo-electric currents for television transmission are explained, 

 and also the need for using short waves and the corresponding limit of 

 distance to which television transmissions can be sent. 



Mr. L. H. PoMEROY. — The design of motor vehicles in the interest of traffic 

 safety (ii.o). 



The paper starts by referring to the degree of concentration called for 

 from motorists to avoid accidents, and deals with design features to reduce 

 motoring fatigue. 



It mentions necessary standards of performance to reduce dangerous 

 traflfic congestion, but regards ultra high maximum speed as unessential. 



Dealing with cars as a whole, it treats body design features as oi primary 

 importance which chassis designers must regard as a condition of design. 

 Body design is discussed in terms of visibility, correct driver's seating 

 position, and suggests that modern streamline body design has been at the 

 expense of the amenities of driver and passenger. 



Reference is made to the modern ' all seats between the axles ' motif, 

 and the mechanical and artistic sacrifices thus entailed. 



Chassis design is dealt with in terms of acceleration and braking, with 

 reference to the allied problems in steering and suspension. 



The importance of silent operation is emphasised and the causes of the 

 noises arising from engines, gears, chassis and body, indicated and discussed. 



The principles of safe driving are mentioned, together with the special 

 difficulties of night driving. 



The paper concludes with a reference to the great work done by engineers 

 and manufacturers in making cars which can be safely driven, and suggests 

 that comparable study and action is called for from Road Authorities and 

 the non -motoring public in the interests of road safety in general. 



Mr. E. G. Herbert. — A continuous hardness test (12.0). 



The new continuous hardness test produces automatically a permanent 

 record of hardness changes occurring in metals during a period of ageing. 

 The basis of the test is a scratch or groove formed by a loaded grooving 

 tool in a specimen slowly traversed under it by clockwork. The ageing 

 period investigated is usually one of 48 or 60 hours, but the period can be 

 extended to as many days or weeks as may be desired. 



The usual type of scratch test with angular or pointed scratching tools 

 having been found unsuitable for exhibiting ageing changes, a new test is 

 introduced in which a groove is rolled in the specimen by a rotating steel 

 ball. This test is shown to be susceptible to changes of hardness due to 

 work-hardening and age-hardening. 



