The best account of this enigmatic, short lived mine is given by the famous A K Hamilton Jenkin:
"With the revival of mining in the early years of the last century, trials were again being made of the lodes in the coastal areas north of Camborne. An adventure known as the NORTH CLIFFS MINE was already in existence in 1823 but it was not until 1844 that another company, bearing the same name, was formed for the purpose of working the lodes on a more extensive scale. In October of that year a sett was granted to John Rule and partners with limits extending "from the point of land which projects into the sea to the northward of Pencobben farm house. [and thence] east to within 200 fathoms of the Tehidy Western Lodge Gate near Green Bank Cliff," the grantees being permitted to work "from the said cliff 400 fathoms in length on any mineral vein they may discover, and as far towards and under the sea as may be practicable, but not to make any pits or shafts on the land side of the cliff without Lady Basset's leave."
The capital of the company consisted of 200 shares, of which Lady Basset herself held ten. A call of 30/- per share was made at the first meeting when Mr. John Rule was appointed purser and manager and Captain Absalom Bennett underground agent, each at a salary of two guineas a month. A second call, of £1 per share, was made in March 1845 and a third, of £2, in June of the same year, costs in the preceding seven months having amounted to £352.10.6. In November 1844 John Phillips was paid the stun of £3 for making a Plan of the nine which comprised ten lodes, viz. Pencobben, Red Cove. Greenbank, South, North, Long Cliff, Tinctured, Black Jack, Green Bank Caunter and Godrevy. Among the first items of expenditure recorded in the cost book was that of boat hire whilst examining the cliff. This was fallowed by the cutting of a new road to reach a level which was then being driven over the South Cavern, the hanging of a chain ladder therein and timbering part of the cavern. Working appears to have been mainly concentrated on the Tinctured and Pencobben Lodes - more particularly on the latter, in reference to which there are frequent mentions of clearing old shafts and levels, sinking a new shaft, driving the adit west, sinking under the adit, and "erecting a Tent". Payments for "watching the mine on Sundays" show that safeguards against marauders was a necessity even in those days.
By July 1846 there was a debt on the mine of £364.14.3.; and no output had been recorded beyond the sale of 4 tons of black jack (zinc ore) to Richard Wearne & Co., and 14 cwt. of lead ore to the Penpol Smelting Company. Notwithstanding this, the time-honoured custom was observed of holding a count dinner for which beef, spirits, lemons and wine were provided at a cost of £6. After this a further call was made of £1 a share. The cost book ends with the minutes of a meeting held on 19th July 1848 when a seventh and final call of 5/- was authorised.
Although the North Cliff Mine had been a failure, the lodes continued to be worked from time to time by individual miners. Among the more successful of these was a tributer named Pendray who is said to have realised considerable profits from silver-lead, the ore being carried up the cliff in sacks and dressed in a small treatment plant at Bell Lake on the Red River.
During the 1920's, the driving of the Camborne sewage tunnel from the Red River valley to the foot of the North Cliffs intersected at least eight lodes or veins, varying in width from a few inches to 5 or 6 feet and carrying galena, blende, copper and iron pyrites, and, in some instances, tin. Whilst the majority showed no signs of having been worked, the tunnel in one place broke into an old men's level which had been excended on a lode for 3 50 feet. In the opinion of mining geologists at the time, the nature of these discoveries was such as to warrant their investigation in depth-either by diamond drilling or other means. Nothing, however, was done to further these suggestions."
Data courtesy of Ben Sum, Helston (1/10/20)
Jenkins, A K H 1965 "Mines and Miners of Cornwall, Vol.10"