The Craigleith Shale Oil Works 1859
A growing demand for artificial light led to the establishment, in 1859, of a firm headed by William Darley Pollard of Collingwood. He erected a plant here to obtain oil through the treatment of local bituminous shales. The process, patented by Pollard, involved the destructive distillation of fragmented shale in cast-iron retorts heated by means of wood. The 27 to 32 tonnes of shale distilled daily yielded 950 litres of crude oil, which was refined into illuminating and heavy lubricating oils. The enterprise, the only one of its kind in the province's history, failed by 1863. The inefficiency of its process made its products uncompetitive after the discoveries of "free" oil at Petrolia and Oil Springs, near Sarnia.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.