Chapter CI: Section 13: Crushing, Grinding & Disintegrating

(_See also p. 36._)

=1988. Eccentric disc grinding mill.= The discs have grooved faces, annular, radial or spiral.

=1989. Grinding face tool,= with segments of stone or emery.

=1990. Huntingdon’s stamp mill.=

=Surface grinding,= filing and polishing; are performed by means of
emery, files, glass and emery paper and cloth, revolving stones and
emery wheels, brushes, endless bands fed with emery and other powders,
&c.

=1990A. Ball mill= for grinding various substances.