lEANSACTIOSS OF SECTION G. 775^ 



where, on reading the address, the operator forwards it to the siding of the con- 

 signee. Subscribers may telephone or otherwise communicate "with the Central 

 about despatch and receipt of trucks, but it is not necessary to do so, since trucks 

 can be delivered into subscribers' sidings, and even unloaded automatically, and 

 then withdrawn again without any attention on the subscriber's part, while trucks 

 placed for despatch by subscribers can be brought into the Central at stated 

 intervals if the operators make it a rule to tap all sidings occasionally for un- 

 announced traffic. Goods could therefore be delivered during the night, and 

 empty trucks sent into the various sidings for next day's traffic. If desired, 

 collisions could be prevented between trucks in motion in the same direction by 

 automatic blocks. In the event of a truck through any accident stopping in the 

 tube, the semaphore connected with the section it is on will remain con- 

 tinuously at danger, and the operator will know that such a stoppage has taken 

 place, together with its position, and take steps to remove it. For instance, he 

 could send au empty truck forward, the speed of which can be reduced to a mini- 

 mum as it approaches the disabled truck by modifying the propelling current until 

 it strikes against the disabled vehicle, when, full current being turned on, both 

 trucks can be forwarded to the consignee or shunted at the next convenient siding. 

 Should trucks by mistake be delivered to the wrong siding, the subscriber would 

 transfer them to the up track, and return them to the Central. The paper claims 

 that such a system would prove of immense service if existing between the chief 

 and branch post-otRces of a city, between railway goods stations, parcel-receiving 

 offices, and large business establishments, &c. The delivery of letters, telegrams, 

 and parcels could be effected by the Post Office to subscriioers without the aid of 

 postmen, while matter for despatch by post and telegrams, together with the 

 money to defray the charges thereon, could be forwarded by subscribers to the 

 Post Office. For Post Office work the system would simply be a great development 

 of the existing pneumatic tubes. Plotels and restaurants could telephone for and 

 obtain in a few minutes viands they may be short of, and enable their customers to 

 choose wine not only from the cellar of the establishment, but from those of every 

 wine merchant on the system. It is not contended that such a system would pay 

 if constructed specially for parcel work, although the surprising developments of 

 the last decade scarcely permit of limits being assigned to the possible developments 

 of the next ; but the author assumes that the construction of subways beneath all 

 the chief thoroughfares of large towns for the purpose of containing electric light 

 and power leads, telephone wires, pipes for gas, fresh water, sea water, hydraulic 

 power, compressed air, and other adjuncts of our complex civilisation, will shortly, 

 become an absolute necessity. A beginning in that direction has been made under 

 the auspices of limited companies in some American citit^s, and we must sooner or 

 later follow suit. Then when that time arrives an electrical parcel exchange could 

 be carried out effectively and economically as part of the scheme. Our footpaths 

 and carriage-ways vAll eventually be laid upon the lids of huge boxes, through 

 which well-lighted pathways, afibrding crossings and short cuts for passengers at 

 congested spots, may even be carried. 



2. The Benier Eot-Air Engine. By M. Benier. 



The question of hot-air or caloric engines has much interested the scientific and 

 engineering world for many years. It has generallj' been admitted that the dis- 

 covery of a really good hot-air engine would be of the greatest importance from 

 economical and other considerations — amongst other advantages, boilers, with 

 attending expense and danger, being entirely dispensed with. 



Appended to this notice are illustrated drawings of the hot-air motor invented 

 by Messrs. Benier Freres. A considerable number of these engines are already in 

 use in France and elsewhere on the Continent for industrial, electric-lighting, and 

 other purposes. Several have been supplied to the French Government for use in 

 lighthouses and fog-horn lightships. In the engine illustrated the air passes 

 through the fire itself directly into the combustion-chamber. With this type of 

 engine a much greater initial pressure can be obtained than in engines using a ■ 



