London: City of London Book Depot. White Street and Finsbury Street, Moorfileds, 1895. boxed set & 8vo. text: xiv, 251 pp. Boxed set & 8vo. (text). Box: 121 x 218 x 37 mm. Complete in 2 compartments and comprising an elaborate set of didactic materials including Cusack’s hinged dihedral panels in mahogany and brass with printed paper labels plus 3 geometrical solids in wood (square, rectangle and hexagon), together with 4 printed envelopes containing sets of various geometrical plain and printed two-dimensional figures (2 of the envelopes are sealed), 2 diagrams on “xylonite” (celluloid), numerous folding diagrams of projective geometry for mounting on the dihedral panels, numerous auxiliary planes made of heavy card for placing within the diagrams, and the original long glass-headed pin. One of the envelopes is chipped, some wear and damage to one or two of the folding figures. The Geometrikon kit is housed in the original pine box, with sliding lid, printed label on lid, somewhat soiled but legible, box a bit worn.
Text: Copiously illustrated. Original blue publisher’s cloth, upper cover and spine lettered and ruled in red, spine a bit sunned, minor bumping. Item #17480
A scarce survivor: a boxed set comprising both two- and three-dimensional geometrical figures in paper, card, celluloid and wood, for use in the classroom to help prepare students for examinations to obtain their school certificates. This amazing educational teaching aid is offered with the accompanying text volume by Armstrong, apparently a “trained and certified teacher, art master, and currently a demonstrator in geometry and perspective at the City of London School of Art and Day Training College, White Street, Moorfields, E.C.” Divided into thirty chapters or “lessons,” the work refers throughout to the Geometrikon and the contents thereof, providing a detailed explanation of its use.