THE PNEUMATIC DESPATCH. 
467 
Railway — and a quarter of a mile long, has been built in the 
Crystal Palace grounds, for passenger traffic. The tunnel, 
which is of fine brickwork, with its closing valves, is already 
completed. The fan- wheel, 2 1 feet in diameter, — which will 
be temporarily worked by a fixed locomotive — is erected and 
enclosed in its plate-iron case; a model station has been 
formed, and the model carriage, built at Manchester, is at 
this moment, in the grounds. It will be travelling in dark- 
ness, no doubt, or rather by lamp-light; but as the front 
head of the front carriage is sucked along by the ex- 
haustion of the tunnel, the air will follow it instantly, and 
afford a plentiful supply of the life-supporting gas to the 
inmates of the carriages, while, just as the balloon, travelling 
at the same velocity as the currents of air which waft it, pre- 
sents a perpetual calm to the aeronaut, no matter how rapidly 
it may progress, so the passengers by the Pneumatic Despatch 
will perceive not the least gusty effects from the gale which 
follows their passage closely up, or that torrent of air which, in 
the reverse method of propulsion, will blow them through in 
the opposite direction. 
One cannot contemplate either the despatch of goods or 
passengers by this means, without perceiving the invaluable 
advantages which this method possesses for the underground 
traffic of our vast metropolis. Passengers will have as rapid 
transit as the locomotive affords, while they will experience 
nothing of the choking sulphurous vapours which the locomo- 
tives leave in our present underground railways. Moreover, 
one line of railway would be sufficient, and no collisions of 
trains could take place. Out of London, the locomotive would 
still be the engine for traffic of all sorts over large tracts of 
country. Again, for goods. To have our over- crowded streets 
relieved of much — perhaps of most — of their heavy traffic, 
and to have the thousands of tons now conveyed by weary 
horses, quietly and silently transmitted unseen beneath our 
roads and houses, will be indeed no slight boon. Still more, 
we may hope to see a network of smaller pipes traversing 
London and its suburbs, for the transmission of parcels. A 
parcel-post thus established will be almost as great a benefit 
as the Penny Postage. 
It seems to ine, also, that great advantage might be taken 
of the system, for effecting communications with or between 
military fortifications. Goods and men might be sucked 
through a tunnel of very great length ; and if such tunnel 
were constructed at some considerable depth, it would be 
unassailable by an enemy. Gunpowder and stores so sent, 
could not be fired, captured, or destroyed ; and although it 
would be a costly thing to make such a means of ingress and 
