from the GNU version of the Collaborative International Dictionary of English
- n. a steam engine having a working beam to transmit power, in distinction from one which has its piston rod attached directly to the crank of the wheel shaft.
from The Century Dictionary and Cyclopedia
- n. A steam-engine in which the motion of the piston is transmitted to the crank by means of an overhead- or working-beam and connecting-rod, as distinct from a direct-action engine and a side-lever engine, in which the motion is communicated by two side-levers or beams below the level of the piston cross-head.
Sorry, no etymologies found.