Plate
2 of the 6 encyclopedias on this shelf carry an entry for Plate. Both are reproduced below, so you can see where they agree and where they differ.
The Encyclopedia of Founding (1892)
Foundry plates are of two kinds principally, being for the purpose of carrying or covering moulds. Those used for carrying are usually plain open-sand plates, with handles or lugs made in a form suitable for the lifting tackle used; whilst the covering plates have dabbers or prickers cast on them for sustaining the loam or sand with which they are covered on the mould or face side. See PRICKERS; LOAM-MOULDING; OPEN-SAND MOULDING. Plate Brass is cast brass for rolling into sheets, and is composed of copper 16, zinc 3. See BRASS. Plate-moulding is simply dividing the pattern to be moulded exactly at the joint or parting, and placing the halves opposite to each other on an iron plate or a board, which is provided with pin-holes exactly corresponding to the interchangeable flasks to be used. Cope and nowel may then be rammed respectively, cope lifted off, plate taken away, and the cope again pinned to place. If distinct plates are made for each side the operations are facilitated somewhat, as all the nowels can be completed at once and the copes follow in succession: the advantage in the latter method is, that the plate is withdrawn from the mould in both cases, while in the former the cope is lifted off the plate-a bad feature when the patterns are not comparatively plain. When more than one pattern are thus treated, and all run from one common gate, it is customary to call it a card of patterns. See MATCH-PLATE. Platen, in moulding-machines, is the upper diaphragm or plate, against which the flask with its containing sand and pattern is forced by pressure from below. See MOULDING-MACHINES.
American Watchmaker and Jeweler (1892)
In a watch or clock the plates form the framework of the movement and in which the holes for the pivots of the train run. The plate in which the pillars are fastened permanently is called the lower or pillar plate, while the removable one is called the top plate. Watches are known as half, three-quarter and full-plate watches, according as the top-plate covers half, three-quarters or all of the lower or pillar plate. In the full-plate model the balance is mounted on the upper side of the top plate, while in the half and three-quarter plate it is mounted upon the pillar plate, thus making a thinner movement.
What Has Changed in the Last Century
The 1892 foundry account describes match-plate moulding as hand work — ramming cope and nowel, lifting the plate away by hand — and that geometry is still the basis of green-sand casting, but the labour is not: automatic flaskless moulding machines now turn out hundreds of moulds an hour, and since the 2000s binder-jet 3D printers have made sand moulds with no pattern plate at all. The watchmaking entry has fared less well. The full-plate movement it describes, with the balance perched on top, was already being crowded out by thinner designs and had effectively vanished from American production by the 1930s, and the quartz movements introduced with Seiko's Astron in December 1969 dispensed with the pillar-and-plate train framework as the normal way to build a watch. Three-quarter plate survives as a deliberate mark of traditional craft, chiefly in German mechanical watches from Glashütte.
Written for this edition, 2026.