Prince of Wales House or Phoenix United Mine is a Grade II Listed building is located in Cornwall National Landscapes, Cornish Mining World Heritage Site and International Dark Skies Park.
The Prince of Wales Engine House holds an important place in the perceived industrial history of the Minions area. Although most mining historians consider the venture to have been an ill-conceived and poorly executed failure, the engine house and its remains have come to symbolise the wider mining heritage of the region. For many local people, it represents not failure, but a source of pride and a reminder of past achievement.
Ecology
This site is a SSSI, on the banks of a metal-rich stream, were found three nationally rare liverwort species that are listed in the Red Data Book of rare and endangered plant species; these being Cephaloziella integerrima, Cephaloziella massalongi and Cephaloziella nicholsonii. The nationally scarce liverwort, Cephaloziella stellulifera was present within the mine. It is unknown if these species are still found at the location and an ecological survey will be undertaken.
Two nationally scarce species of moss, Gymnostomum viridulum and Gymnostomum calcareum, are supported on the site. The mine is one of only two sites in the world where Cornish path moss (Ditrichum cornubicum) grows, the other being Crow’s Nest. This moss is a pioneer species of bare or sparsely vegetated, mine-waste laden soils.
History of Prince of Wales Engine House
In 1907, the Cosmopolitan Proprietary Co. Ltd. took over the lease of the old Phoenix United, East Phoenix, and Dunsley Wheal Phoenix sett. The proceeding company to this is recorded as Birbeck, Moreton, Thompson and Co. The exact reasons for reworking these mines are unclear, but it was likely influenced by persistent rumours that valuable tin deposits still remained underground. Such beliefs were common in mining areas, where stories often circulated that earlier miners had been forced to abandon rich ground before it was fully exploited.
Geological considerations may also have played a role in the decision. Reports suggested that the ground to the east had not been completely explored, offering hope for new discoveries. However, this optimism seems questionable given that mining in the area had already been carried out for around 150 years, often at increasing depths. It is therefore unlikely that significant, easily accessible deposits had simply been overlooked by previous generations of miners.
Despite these doubts, work began with considerable enthusiasm and optimism, probably intended to inspire confidence among potential investors and shareholders. A branch tramroad was added to the Liskeard and Caradon Railway it was installed to connect the mine to the dressing floors, improving the movement of materials. Around the same time, a large 80-inch pumping engine designed by Nicholas Trestrail was ordered from Holman’s of Camborne. Construction also began on a new shaft to the south of the earlier workings, located on what had previously been undeveloped ground.
The scale of development was substantial, involving the installation of five Lancashire boilers, an air compressor with a receiver, and a Robey engine used for hauling material from the shaft. Alongside this machinery, numerous ancillary buildings were constructed, including a boiler house, winding engine house, compressor house, and a carpenter’s shop. New dressing floors were also built, equipped with a twelve-head stamp system for crushing ore, indicating a serious commitment to processing extracted material.
In addition to new construction, efforts were made to extend and improve existing workings. The Stowes Adit was reopened and re-timbered to provide access to the western part of the sett, and refurbishment work began on one of the older Stowes shafts. Overall, the project demonstrates a significant level of investment and ambition, driven by the belief that untapped mineral wealth remained underground. However, with hindsight, this optimism appears to have been misplaced, contributing to the mine’s eventual failure despite the scale of effort and resources committed.
By 1909, the engine had been brought into operation and the shaft was named after the Prince of Wales, who visited the site on 10th June 1909 with his wife Mary and held a mineral interest in the mine. This was part of a three-day tour of Cornwall. On the day of their visit they toured the interior of the mine, they sat for their lunch in a marque outside the Count house before heading for a cream tea at Cotehele.
It soon became evident that the reserves were not as rich as anticipated, and the Holmes engine was incapable of coping with the volume of water that needed to be pumped. Air-operated Cameron pumps were described by one writer as “perhaps the most expensive of all possible ways to do the work” – were employed in an attempt to drain years of accumulated water from a vast area of workings. The unfortunate reality was that earlier miners had already “picked the eyes” out of the most profitable ground before the mine’s earlier closure.
By July 1914, the decision was made to abandon the project. The Duchy subsequently purchased the engine in the hope that a new operator might revive the mine, but no such interest materialised. By 1935, maintenance of the engine was deemed no longer worthwhile; it was dismantled and ultimately sold for scrap.
