The Ipswich Advertiser - Monday 2 March 1863
The latest mode of sending mail-bags and parcels is by means of atmospheric air. This has been adopted in London by the Pneumatic Despatch Company, on a comparatively small scale; but the principle is capable of wide extension, and there appears but little doubt that, after a short time, a great deal of the merchandise of the metropolis will be sent from one point to another through underground tubes. On a piece of waste ground, at the Euston-square station of the North-Western Railway, an engine house has been built, and this shelters engine of some 20-horse power, together with gigantic disc of some 21 feet in diameter, and which is hung upon the horizontal crank shaft of the engine. This disc, which is hollow, and of wrought iron, is virtually an air-pump, and it is divided into a number small chambers. When the disc is in motion, these, like so many mechanical fans, gather air at the centre and emit it the circumference. This centrifugal disc makes some 300 revolutions per minute; and as its centre is to be in direct communication with the interior of the conveyance, or vacuum tube, it is clear that this latter may be exhausted to extent governed by the speed of the disc, and the weight the relief or regulating valve opening into the tube. The height of the tubes, from floor to roof, so to speak, is 2 feet 8 inches, and their width also is 2 feet 8 inches. The upper part or roof is semicircular, while the lower part is nearly flat.
The carriages themselves are made of stout boiler plate. They are about 4 feet 6 inches in length, have a deep hold for the reception of their cargoes of letters, parcels, merchandise, and are each mounted on four small wheels of cast-iron. The carriages are of the precise form of the tube, and though they by no means fit its interior closely, they yet may be said to represent pistons. About quarter of mile of this tubing has been laid down, and it connects the engine-house at Euston with the North-Western District Post-office in Eversholtstreet, Camden-town. At each end of the conveyance pipe an iron cover of sufficient area to seal its mouth is hinged. Such are the main features of the apparatus of the Pneumatic Despatch Company, now in operation.
it will now be understood that it quite possible to pump the air from the conveyance pipe. Well, then, supposing it be desired to transfer a loaded carriage from the Postoffice to the railway station, it will be simply necessary to push it (the carriage) forward on rails corresponding with those in the inside of the tube, close the engine-house end, start the disc, remove the air from the front of the carriage, and allow ths external atmosphere to push it forward to its destination. The speed at which it will travel will depend on the extent of the vacuum, which again detemined as we have described. This operation may be justly termed "sucking" the mail.
At the head of this paper we speak of "blowing" the mail, well as sucking it. This operation the Pneumatic Despatch Company do by inverting the action of the disc, and causing it thus to force or blow air into the conveyance pipe, instead of pumping it out.
Arrangements have been entered into with the North-Western Railway, Messrs. Pickford and Co., and Messrs. Chaplin and Horne with a view to an early and general development of the system, by a 48-inch tube of five miles, which will connect the North-Western Railway with Holborn, the General Postoffice, Gresham-street, and Charing, cross, at a cost of £131,260.
Messrs. Rimmell and Clarke are the engineers, and James Watt and Co. constructed the engine and the machinery.
The author of this article is unknown. Since it is published far more than 70 years ago, it is believed to be in the Public Domain.