Coradi planimeter and map, 1886.

Planimeter, Swis, 1894.

Induction compensator, c.1900.

Eutectic carbon steel, light micrograph, 1990s.

Mudstone. Light micrograph in differential

Aluminium bronze. Light micrograph.

Neolithic slag, light micrograph, 1990s.

Anodised extruded aluminium, light micrograph, 1990s.

Spheroidal graphite (etched), light micrograph, 1990s.

Ascorbic acid, light micrograph, 1990s.

Galena, light micrograph, 1990s.

Colby's compensation bars, Ireland, 1827-1828.