from The Century Dictionary and Cyclopedia
- n. The bed supporting the carriage of a printing-press.
- n. The bed of knives immediately beneath the cylinder of a pulping-engine.
- n. In ordnance, a plate used in building up grape and canister into a cylinder ready for loading into a gun.
Sorry, no etymologies found.
The process unavoidably starts with "assumption" as the bottom-plate for all concepts controlling the structure.