This model shows 'undercut' strata: when the layers of rock are inclined at a steeper angle than the eroded slope, the resulting 'vee pattern' points downhill. Thomas Sopwith (1803 - 1879) was an eminent geologist and civil engineer who pioneered methods of representing geological features. This set of wooden models were designed to represent geological situations with faults, folds, inclines and strata that were particularly relevant to the mining industry.