DISCOVERY 



263 



far more pleasing results obtained by making unim- 

 portant roads and paths narrow and light in con- 

 struction. This does not mean that the houses facing 

 each other will be closer together, but that additional 

 space will be available for front gardens and grass 

 margins. 



In working out these schemes, shops can be built as 

 shops, not as houses which are afterwards converted 

 more or less inefficiently. A shopping centre can in 

 fact be arranged for, and suitable sites can also be 

 reser\'ed for allotments, playing-fields, schools, libraries, 

 churches, etc. 



When the house shortage has been adequately dealt 

 with, the existing bad houses can be replaced by proper 

 homes, in some cases on the same sites, but generally in 

 more pleasant surroundings. The sites thus cleared 

 may be used as open spaces, or as sites for works 

 extensions and business premises, and in making these 

 alterations great street improvements may be effected. 



In order that these changes may be the most bene- 

 ficial, the whole problem of the present town or district 

 must be considered carefully, and an outline scheme 

 for its future development worked out. 



It has been suggested that some towns are already 

 sufficiently large, and that their future development 

 should be in the form of separate villages organically 

 connected with the towns but separated from them by 

 belts of open country. Whether this suggestion is 

 adopted or not, a carefully-worked-out scheme will 

 give far better results than the haphazard methods of 

 the past. 



BOOKS RECOMMENDED 

 New Townsmen, New Towns after the War (J. M. Dent & Sons, 



Ltd., IS.). 

 J. S. Nettlefold, Practical Housing (Garden City Press, is.). 

 Richard Reiss.TAe Home I Want (Hodder & Stoughton, 2s. 6d.). 

 Martin, The Small House (.\lston Rivers, 2s.). 

 Allen. The Cheap Cottage and Small House (Batsford, 8s. 6d.). 

 Gotch, The Growth of the English House (Batsford, los.). 

 Unwin, Town Planning in Practice (Fisher Unwin, 42s.). 



A Unique Transmission 

 System 



By W. Harold Johnson, M.A. 



The transmission of power has always been one of the 

 most acute of engineering problems. It is not that the 

 transmission in itself offers any insuperable difficulties, 

 but that as soon as one has to turn comers, as one nearly 

 always has sooner or later in any transmission system, 

 there is a considerable loss in efi&ciency. The steam 



engine that is generally coupled direct to the useful 

 implement that it operates, whether it be the propeller 

 of a ship, the wheels of a railway engine, or the spindle 

 of an electric dynamo, is much more easily handled 

 than is the comparatively new prime mover that bids 

 fair to oust the steam engine from all the spheres that 

 the older unit has previously occupied unassailed. 

 And the internal combustion engine is above all things 

 primarily suited for use in mechanically propelled 

 vehicles, in which, with the solitary exception of the 

 aeroplane, the turning of corners in the transmission 

 system is a difficulty that has to be encountered and 

 overcome. 



The internal combustion engine relies for its power 

 output primarily on its speed, and consequently there 

 is incorporated in every motor-car mechanism known 

 as the change-speed gear, or simply the gear box, which 

 has the effect of making possible a change in ratio 

 between the engine and road wheels, but at the same 

 time necessitates the turning of comers by the power 

 in its path from engine to back axle. On a normal car 

 the engine makes four revolutions for every single 

 revolution of the back wheel when the car is travelling 

 on what is known as top gear. On bottom gear this 

 number of revolutions is increased up to as many as 

 16 to I, and the intermediate gears, that may be one or 

 two in number, generally offer ratios of something like 

 6"5 and 10 to i, or if there is only one intermediate 

 ratio this generally is in the neighbourhood of 7-5. The 

 gear box, while quite reliable and satisfactory enough 

 in the hands of a careful and experienced driver, is one 

 of the most delicate components of the car, and is liable 

 to considerable damage as the result of careless handling. 

 Various means have been suggested to enable its entire 

 abolition from the car chassis together with that of the 

 clutch, which is an essential componentfor the operation 

 of the gear box, although it is constructed as an en- 

 tirely separate unit from it. Hydraulic transmission 

 systems have been suggested and tried with varying 

 success, the extent of which may be judged from the 

 fact that not a single hydraulic system has ever " caught 

 on " in technical circles. 



The idea of using electricity for the transmission has 

 been employed satisfactorily on the Tilling-Stevens 

 heavy chassis for many years, the essentials of this 

 system consisting of an electric dynamo operated by 

 the engine and generating current for a motor which 

 drives the back axle in the ordinary way. But an electric 

 transmission system that is entirely new to this country 

 has recently made its appearance under the name of 

 the Entz, fitted to an American car known in America 

 as the Owen Magnetic, but to be called over here the 

 Crown Magnetic, and in due course, it is hoped, to be 

 manufactured in this country. The transmission itself 

 cannot be described as absolutely new, for the Owen 



