Pneumatic tubes. See [Section 19]. Valves for do., [No. 1638].

[1085]. Is an improved form of worm having no centre shaft. “Patent Anti-Friction Conveyor.”

[1086]. Elevator, or band and buckets, may be run in any position.

[1087] & [1088]. Endless web and roller devices for conveying sheets of paper, for printing or folding.

See also Raising and Lowering, [Section 69].

[Larger plate.]

Section 58.—PACKINGS, JOINTS, STUFFING BOXES, &c.

PISTONS.

[1089]. Piston with junk ring; the packing is sometimes cast iron, steel, brass, or phosphor bronze rings, or even hemp or asbestos.