Treffry trained in civil engineering, one of his earliest works was the building of a new quay in Fowey to take larger vessels. It was also at this time that he first became involved with mining becoming a partner in Wheal Regent Copper Mine at Crinnis near Par. Two years later he became a partner in Fowey Consuls mine at Tywardreath and manager of Lanscroft mine. By 1822, the two mines had amalgamated and he had taken full control. Fowey Consuls being the most productive in Cornwall and employed 1,680 persons making Treffry the largest local employer. It was said that 100 mules and 30 horses were not enough to transport the ore the four miles to Fowey Harbour.
Wheal Regent later became part of West Crinnis Mine
Mining in St Austell Area