Bearings running under water are generally lined with strips of lignum vitæ and require no lubricant.

So-called self-lubricator bearings are in use, lined with strips of patent composition metal.

[Larger plate.]

[834]. Centre bearing, with annular grip, for a heavy centre piece or car bogie.

[835]. Centre bearing, with allowance for some amount of oscillation.

Coupled bearings. [No. 671].

Section 47.—PLATE WORK.

[836]. Single riveted lap joint.