2-798-848 - The Print Collector/Heritage Images

Portion of the tube on the line, 1845. Diagram showing part of the track of an atmospheric railway, a system using air pressure for locomotion, invented by Clegg and Samuda. 'A large tube is laid down in the centre of a line of rails. This tube has an opening at the top, which is closed by a valve, formed of a leather strap, covered with short plates of iron above and below. Now, the strap being broader than the plates, it is pressed against the top of the pipe by a succession of long rods, screwed down with hook bolts, and thus forming a hinge. On the side on which the valve opens is a groove, which is filled with a composition of wax and tallow. It is evident that when the valve is raised, there will be space enough for a bent plate of iron to pass into the tube.' From "Illustrated London News", 1845, Vol VII.