Henry Boynes was captain of the mine in the early 18th-century and opened a ″deep adit level,″ which was driven to the Corpus Christi lode in the higher mine. The first steam-engine was put to work at Carnyorth Moor (later part of the Botallack sett) in either 1795 or about 1810, depending on the source. In the first half of the 19th-century, the average price of Botallack tin was £64 4s a ton. The abolition of tin duty of 4s per 120 lbs to the Duke of Cornwall in 1838 helped to keep the mine operating despite a decline in the price of tin to £45 per ton. In the 1860s a new diagonal shaft was dug. A visit by the Prince and Princess of Wales in 1865, when they descended the shaft, created a mini-boom in tourism, causing the mine operators to charge visitors a guinea per person.