A Guide to the Mineral Gallery ... With an Introduction to the study of Minerals. [By L. Fletcher
A visitor's guide to the Mineral Gallery of the British Museum (Natural History), written by its keeper Lazarus Fletcher and published in London in 1888, with an appended primer on crystallography for general museum-goers and students. The plates are fine outline diagrams of crystal forms — cube, octahedron, rhombic dodecahedron, prisms — with lettered faces, edges and dashed hidden lines, alongside soft grey figures of concentric oval rings crossed by axes; useful for wireframe geometry, technical labelling conventions, and maze-like radial ornament.
