The following cites another potential source of information:
"The numerous mines in this area [Scorrier] are mostly shallow, very few of them attained a depth of 1,000 ft. Hitherto the production has been principally copper, though a total of over 10,000 tons of black tin has been raised by the various mines in this district, and wolfram in some quantity was making its aoppearance in some of the deeper workings."
"...developments in the Scorrier district ceased at wahta was probably the transition horizon between copper and tin."
"An immenense amount of information concerning this area [Scorrier] was collected by Mr.C.E.Trestrail of Redruth and embodied by him in a series of reports; the information which these contain should be invaluable in any future large-scale planning of mining here. The prospects in this extensive area are, possibly, better than in any other part of Cornwall not at present being worked."
K.F.G.Hosking & J.H.Trouson "The Mineral Potential of Cornwall", pp.355-369 in "The Future of Non-Ferrous Mining in Great Britain and Ireland: a symposium" (London: Institution of Mining & Metallurgy, 1959), the above quotes are from p.366.
In this volume is a contribution from a G.A.Moorhead, described as Director, Silvermines Lead & Zinc Co Ltd, to the discussion on Irish mines and prospects, mentioning this company's Irish barytes output. He did not contribute to the discussion of Cornish mines and prospects. Is this the same G.Moorhead?
Is this the same person as the partner in Richards, Moorhead & Laing?
J.H.Trouson's paper "Practical Considerations in Developing Old Cornish Mines", pp.371-394 in the above volume is specially interesting.
This volume mentions "At the North Cliffs, near Camborne, a tunnel was driven in order to convey sewage to the sea. During the work a numbe rof lodes had been intersected containing varying amounts of chacopyrite, arsenopyrite, galena and spaherite. These lodes were mapped and sampled, and the individual responsible for the work noted three zones that looked promising from the point of view of the miner." (K.F.Hosking: contribution to discussion on Ore testing, pp. pp.473-5). Is this possibly the tunnel mentioned on a thread a month or two ago?