The region was predominantly populated by people who speak Welsh as a first language, and it was known as Cors y Bryniau (the boggy hills in English), and more colloquially as Chwarel y Gors (swamp quarry).

[3] Next came William W Griffith, the works manager of Moelwyn quarry, who with Benjamin Lloyd of the Grapes Inn, Maentwrog, applied for a take note for 185 acres (75 ha) in 1861.

Men were set to work constructing a tunnel at a higher level, and they hit slatey rock soon afterwards, at which point a lease replaced the take note.

[5] Morris Jones, formerly of Braich-Rhydd quarry, was in charge of operations, and most of the early work involved removing overburden, but he thought the rock beneath was of good quality.

As Welbourne was not working his land, he consented to a change of lease, but the Alexandra company could not find enough ground to tip the spoil, or the cost of constructing the tunnel, and nothing was done.

As consulting engineer, he suggested a deep adit, driven from the north of the site, which would intercept two slate veins which were clearly visible in the adjacent Moel Tryfan quarry.

Construction started in 1869, but the company became bankrupt, and Sir Thomas Bateson, acting as liquidator, sold the quarry to his brother Samuel for £990.

[7] One of the first uses of an air compressor and mechanical drilling in the slate quarrying industry helped to speed up progress, but the tunnel failed to find the first vein after it had been driven for 288 yards (263 m).

A change in the dip of the rock below ground meant that it was not encountered until the tunnel reached 410 yards (370 m), by which time £33,000 had been spent, with £19,000 of that being Bateson's own money.

[9] Samuel Bateson seems to have spent another £15,000 of his own money on development, and had also bailed out the North Wales Narrow Gauge Railways to stop them from becoming bankrupt.

Although the slate industry suffered a slump in the 1880s, Menzies pushed ahead, and the number of workers increased from 180 to 230 as the decade progressed.

A large fall of rock from the sides of the quarry occurred in 1888, which took about a year to clear, and the main purple-red vein was interrupted by a granite pillar at the north-east end of the workings.

The driver was severely scalded, and the accident resulted in the agent and the company both being fined £50 for failing to adhere to boiler inspection regulations.

[15] The Crown inspector noted that the quality of rock being extracted was improving as galleries to the east got deeper, but that collapses were still a problem in the west of the quarry.

[18] Menzies again cut wages in 1913, and the dispute led to the North Wales Quarrymen's Union calling their second official strike in the 40 years since they had started representing the industry.

The new start was short lived, as the quarry closed on 15 August 1914, with the onset of World War I. Menzies was called up in 1915, and the secretary, Alfred H Richards, took over.

[19] In the aftermath of World War I, many of the smaller slate quarries had little chance of restarting after four years of shortages, both of men and materials.

[21] They employed 78 men initially, and operated at a loss for the first seven months, but made a small profit by the end of the first year, as a result of output from Cilgwyn.

Violent storms damaged two of the cableway towers, and there were major rock falls in Alexandra No.1 pit and the main working face at Moel Tryfan, resulting in the company reporting it first losses in 1928.

[23] The quarries were closed from January to April 1930, due to heavy snow, there were large cracks above the faces at both Moel Tryfan and Alexandra.

The company pleaded with the government for some assistance, by deferring payment of debenture interest, and suggested that the Crown Commissioners should hire two steam excavators to remove huge amounts of overburden.

[26] Small groups of men were employed to work the tips for rock which had been discarded, but could now be used, while the job of removing the overburden from Alexandra quarry began.

[27] Former workers from the Amalgamated Slate Association were employed by the government scheme to remove the overburden at Alexandra quarry, and a job-sharing rota was used to ensure that all of the unemployed were able to gain some income.

By the outbreak of the Second World War, the quarry was working on a smaller scale, although additional slates were still being produced by reworking the old tips, and granite was extracted for the County Council.

[30] There was also unrest in the quarries from the 1870s, and following two strikes in 1874, membership of the North Wales Quarrymen's Union increased significantly, with around two-thirds of all workers joining.