DETAILS OP SCREW ENGINES. 273

this section will commence with a notice ofthe cylinders and pistons for trunk engines.Messrs. J. and G. Eennie arrange the detailunder notice as depicted by Fig. 113. The

Pig. 113.

I. RENNIES CYLINDER AND SINGLE TRUNK PISTON.

plan, being in section, shows the piston athalf stroke ; and the elevation, half in sectionand half complete, with the piston omitted,represents the form of the cylinder and thedirection of the exhaust passage. Thelatter, it will be noticed, passes over the body°f the cylinder, where it connects directly^itli the condenser,—as shown in plan by%• 4, page 44. _

The illustration, Fig. 113, is that of a cylin-

der of 100 horse power nominal, the principaldimensions being as follows:—

r Et. In.

Diameter of Cylinder 7

7 .37

Diameter of Trunk .

. 1 8

Length of Stroke

. 2 0

Length of Connecting Bod

. 5 0

Depth of Piston

. 0 8

The mode of adjusting

the brasses for the

connecting rod at the piston end of the trunkhas been a matter of the deepest thought bythose who advocate trunk engines. TheMessrs. Eennie have two modes of overcomingthe difficulties, one relating to a single-endconnecting rod, and the other for the double

Pig. 114.

Messrs, rennie’s mode oe adjusting the brasses eor

THE CONNECTING ROD PIN.

or forked-end type. The arrangement, shownby Fig. 114, is a single plummer-block, cast

2 R