Slate was discovered in the vicinity of Rhosydd in the early 1830s. Two men from
Croesor found it and assumed that it was on the estate of Croesor Fawr. They therefore asked the owner, William Turner, for a take-note, which would allow them to quarry the rock. It was also found by Meredydd Jones of Maenofferen, but he assumed that it was on the Cwmorthin Ucha estate, which was owned by
William Ormsby Gore, and so he approached Ormsby Gore's agent for a take-note. As the boundary between the two estates was not clearly defined in this region, a court case followed in 1833, to decide where the boundary should be. The result was that Rhosydd was part of the Cwmorthin Ucha estate, and the Ormsby Gores issued take-notes and later leases. Small scale working began, but the site was not easily accessible, as the workings were some above sea level, in an area of boggy moorland. A Mr Mathews from
Aberystwyth obtained a lease, and created the first adit, but appears to have done little more. Another lease was issued to two speculators in 1850, but it was not taken up. In 1852, Edward Barker obtained a take-note, which he then transferred to a partnership. Barker was the son of Ormsby Gore's agent, while the partnership consisted of a surgeon called William Taylor, a warehouseman called John Pearce, both from
London, and John Harper, who was from Porthmadog. Harper briefly acted as managing director, but was soon replaced by a naval captain called Richard Oliver. The agent or general manager was Thomas Jones, who had assisted Barker in his search for slate. On 27 June 1853, the partnership became the Rhosydd Slate Company, which negotiated the conversion of the take-note into a lease in September. Finished slates were carried by the
Ffestiniog Railway in 1854, and in 1855 some Rhosydd slates were shipped from
Porthmadog. In the following year, the
Joint Stock Companies Act 1856 was passed by parliament, and the quarrying company became the Rhosydd Slate Company Ltd on 7 November, under the terms of that act. Finished slates were transported by pack horse when quarrying began. The route taken probably followed a well-built path that starts near the highest workings and runs between the peak of
Moelwyn Mawr to its west and Llyn Stwlan to its east, before turning to the west and descending Cwm Maesgwm to reach the
Maentwrog to
Aberglaslyn turnpike road. As the quarry developed, and workings were opened up to the north, a more obvious route was that down Cwm Orthin to the east, which reached the Ffestiniog Railway at
Tanygrisiau. However, Cwmorthin objected, and restricted the use of this route by prohibiting the use of carts, which they enforced by erecting a gate at Ty Gwyn, about above the Ffestiniog Railway. Wheeled carts would have been difficult to control, because of the steep gradients, and sledges may have been used. These were known as "car llusg" in Welsh, which was often translated as "cart". The company was created with a nominal capital of £50,000, and all the shares had been issued by 1862. Most of the money came from London, with some from
Bath, but very little from local sources. To raise more money, £30,000 in
debentures were then issued. A new lease was obtained in October 1859, on terms which were favourable compared to many other quarries in the area; royalties of two shillings (10p) per ton were payable, whereas five shillings (25p) was more common. Transportation improved in 1864, with the opening of the
Croesor Tramway. Construction began in 1862 without an
Act of Parliament, by obtaining
wayleaves for the route from Porthmadog to the foot of the first
incline at Garreg Hylldrem. Beyond there, it was effectively a private tramway, as it was built on land leased to the owners of various quarries which it served. There were two inclines at Garreg Hylldrem, and a third at Blaencwm. After a short level section, the tramway divided, with one branch ascending a large incline to the
Croesor quarry, and another ascending to the Rhosydd exit tramway. Both inclines descended by around and were the two highest single-pitch inclines in Wales. A deed of
mutual covenant was signed on 1 October 1863 by the Rhosydd Slate Company Ltd and Hugh Beaver Roberts, the builder and owner of the Croesor Tramway, to formalise the building of the incline and connecting tramway. It also set the tolls for use of the incline at 2d (0.8p) per ton, reducing to 1d. By this time, slate was being worked on five levels, and there were two adits, one of , with a second of . The first four wagons loaded with a total of 7.4 tons of slates descended the incline on 1 August 1864, the day on which the Croesor Tramway officially opened. The first month was exceptional, with the quarry sending 284 tons of slates to Porthmadog, after which it levelled out at around 200 tons per month. Coal traffic in the reverse direction developed, some of it for the quarry and some for the quarrymen's barracks. A proposed restructuring of the company in 1865 to raise additional capital did not occur, but the capital of the original company was increased to £125,000 in the following year. In March 1871, the lease was renewed for a further 42 years, but the company was soon in difficulties. Adequate returns could not be made on the large amount of money sunk into development, and on 27 June 1873, it went into
voluntary liquidation.
Second phase A sale notice produced in 1874 in preparation for an auction of the quarry and plant claimed that development work at Rhosydd had cost £150,000. The auction took place in
Manchester on 27 June 1874, and the quarry was sold for just £29,500. The buyers created the New Rhosydd Slate Quarry Company Ltd on 10 October, and whereas the previous company had been dominated by Englishmen, three-quarters of the initial shares in the new company were bought by local people, from Ffestiniog, Porthmadog and the surrounding area. There were bankers, doctors, magistrates, merchants, quarry agents, solicitors and "gentlemen". The new company set its authorised capital at £80,000, consisting of 1,600 shares valued at £50 each, but only £44,000 was subscribed. Richard Hughes of Ynystowyn, Porthmadog acted as secretary until 1921, and the company office was in Ynystowyn. All of the directors were Welshmen, and remained so for the life of the quarry. Good dividends were paid between 1876 and 1889, but then profitability declined. In 1900, a large section of the underground workings collapsed, in what was known as the "great fall". The company now had to create a new quarry, with the only finance coming from their revenue account. Evan Jones took on the job of opening up new workings in 1906, when the previous agent, William W Morris, was retired, having shown that he was unable to complete such a task. Jones largely succeeded in carrying out this brief, as he was supported by three board members with a working knowledge of mining. The first was Morris, who had been given a seat on the board when he was retired; the second was also the agent at
Llechwedd, another major quarry in
Blaenau Ffestiniog; and the third owned several quarries near
Harlech. Complete success was thwarted by a serious slump in the slate trade in the period leading up the
First World War, and then by the war itself. The quarry was shut down in 1914, as slate quarrying was declared to be a "non-essential industry", although two men were retained to maintain it, and it reopened when the war had finished, in 1919. However, company finances were in a poor state, and when the directors received an offer to purchase the quarry, the company went into voluntary liquidation on 12 July 1921, eleven days after its assets had been sold for £23,798. It was bought by two members of the Colman family, better known for producing the
Colman's brand of
mustard. They had also bought the Groesyddwyafon quarry in 1920, and continued to work both much as before, but struggled to find markets for the product, and Rhosydd closed on 13 September 1930. As during the First World War, two caretakers were retained, and the pumps continued to operate, in the hope that it could be reopened. ==Geology==