40 ANNUAL OF SCIENTIFIC DISCOVERY. 



tion and repulsion, &c., rest and motion are one. Hence, if the time 

 should ever come, when 1,000 miles an hour can be done, old ladies 

 and children will be no more inconvenienced than now, and in all prob- 

 ability not near as much." Journal Franklin Institute. 



THE PNEUMATIC RAILWAY. 



In former numbers of the Annual of Scientific Discovery ( see vol. for 

 1864, p. 21 ), we have described the workings of the so-called "Pneumatic 

 Despatch" as used in London and elsewhere. During the past year the 

 directors of the Cry.-t il Palace, near London, have constructed upon the 

 same principle a pneumatic railway, consisting of a brickwork tunnel, or 

 tube, about 600 yards long, 10 ft. high, and 9 ft. wide. This tube, 

 Avhich is capable of admitting an ordinary size railway carriage, is laid 

 with a single line of rails, fitted with opening and closing valve-; at either 

 extremity, and supplied with all the other requisite apparatus for pro- 

 pelling passenger trains on the pneumatic principle. 



The object of laying down this experimental line was to afford, both to 

 the scientific world and the traveling public, a practical demonstration of 

 the applicability to passenger tr iffic of the motive power already em- 

 ployed by the Pneumatic Despatch Company in the conveyance of let- 

 ters and parcels. 



Tiie trial trips recently made with this railway are reported as per- 

 fectly successful, and are thus described in the London Times, of Au- 

 gust 20, 1804 : The pneumatic principle of propulsion is very simple. 

 It has been likened to the action of a pea-shooter, a rough kind of com- 







parison, perhaps, yet one sufficiently accurate as a popular illustration. 

 The tunnel may be taken to represent the pea-shooter, and the train the 

 pea, which is driven along in one direction by a strong blast of air, and 

 drawn back again in the opposite direction by the exhaustion of the 

 air in front of it. The train may be said, in fact, to be blown through 

 the tube on the down journey, and sucked through it on the return 

 journey. It must not, however, be supposed that the passengers are de- 

 posited at their destination with a sudden jerk, as the simile we have 

 used might seem to imply. Such an inconvenience is entirely obviated 

 by the mechanical arrangements employed. The motion is throughout 

 smooth, easy, and agreeable, and the stoppages ars effected gently and 

 gradually. Indeed, when it is considered that the curve in the tunnel is 

 unusu diy sharp, being of eight chains radius, and that the gradients are 

 as high as one in fifteen, it is surprising that the motion should be so 

 much sieadier and pleasanter than ordinary railway traveling. The 

 journey of 600 yards was performed either way in about 50 seconds, 

 with an atmosphere pressure of only two and one half ounces to the 

 square inch ; but a higher rate of speed, if desirable, can easily be ob- 

 tained consistently with s.ifjty. Indeed, one great incidental advantage 

 of this species of loco -notion is that it excludes all risk of the collisions 

 occasionally attendant on railway traveling; for it is plain that no two 

 trains coukLev-er run full tilt against each other where all the propelling 

 force is expended in one direction at one time. The worst mishap which 

 it is said could well happen is that, owing to some sudden failure in the 

 machinery, the train might be abruptly brought to a dead stop in the 

 middle of the tunnel, when the passengers would have to alight from the 



