Models illustrating John Farey's figures of stratified masses

Abstract

A partial collection of laminated wooden models illustrative of John Farey's (1766–1826) ideas on the effects of faulting on stratified masses, expressed as two plates of 56 block diagrams in his ‘General View of the Agriculture and Minerals of Derbyshire’ published in 1811, are preserved in the collection of the Geological Society of London. The models have been identified and described. An economical method of construction involved sawing two conjoined laminated blocks along a ‘plane of denudation’, thus giving two distinct models illustrative of different diagrams. Also illustrated are the patterns of strata formed by cutting cylindrical valleys across the models. Farey foresaw the possibility of illustrating the effect of conical and branching excavations on outcrop patterns in various combinations of tilted and faulted strata. The diagrams were intended as a visual aid to the mineral surveyor in deciphering fault displacements in the simple stratified successions of strata in the mining area of Derbyshire.