204 — ON THE DETRITAL TIN-ORE OF CORNWALL. 
the bed of Restronguet-creek is some twelve feet below high-water 
at spring-tide—a shaft has lately been sunk through the under- 
mentioned deposits,—* 
(1). Mud of the river (very soft) ........ ovehoehskelerelctopsieveloheteleisrer 6 feet ;— 
(2). Mud and coarse sand ..........6> Bloke exe let oelevedsoxsveverspereceiener eiieaad 
(jo Wine! Casnclsnee)) a55bo0050dboacosedadcodostansonoooONdOS O go 3 
(4). Mud, mixed with great quantities of Oyster- Hhelleu sce 1D Save 
(Bo Whol (amiclsineel) coonsacaoocuce dH o0000000;n0000000000 BL 45. 8 
(6). Zin-ground (6 inches to 6 feet) ....5...........000. mean 4.4) = 
The Shelf; homogeneous blue or buff-coloured clay-slate. 
Another section, in the same neighbourhood, presents,—t 
(1). Soft river-Mud .....scecessceccccccccsrsrscereveses 7 to 9 feet ;— 
(Bo iineresenael piel mGlSS bo 55005d0a90 boo DDOdanodo0G0050000 8) 95 9 
(3). Blue mud mixed with Oyster, Cockle, and other shells...... og 28 
(4): Stilt blue mud; without Shells cocci ste cleele win cieiei nies BG 45 8 
(5). Tin-ground (Subangular masses of granite, slate, elvan, quartz, 
quartzose slate-capel, and tin-ore in large masses, plenti- 
fully interspersed with smaller grains ........ 6inchesto6 ,, ; 
(6). The Shelf ; clay-slate. 
The tin-ground was no where else so rich as at the confluence of 
the Carnon valley with the vales which extend respectively through 
Perran-Wharf and Ponsnooth to the northern slope of Carn 
Menelez, and from Tarnon-dean through Perran-well (the Smelting- 
house glen) to Gilly.{ As might have been anticipated, operations 
were undertaken in both ; pee speculations—they were alike 
unsuccessful ; through, nadlomial se they were of great interest. 
At perhaps one-third of the distance between the Carnon 
embankment and Perran-wharf an artificial mound was raised 
above the level of high-water ; and, through it, a shaft penetrated 
to the (shelf) rock, whilst drifts are extended, laying open both 
the tin-ground and the bed of vegetable matter above it. As the 
works were imperfectly ventilated, imflammable gas sometimes 
accumulated ; and—more than once—the workmen, who worked 
with unprotected candles, were scorched by its explosion.§ 
* For these particulars I am indebted to Mr. Richard Taylor, F.G.S. ; 
and Mr. Charles Dyke Taylor. 
+ For this section I have to thank Mr, Whitley, C.E.; F.M.S.; Secretary 
of the Royal Institution of Cornwall. 
+ Henwood,: Cornwall Geol : Trans : v, p. 60. 
§ Ibid, viii, p. 453, 
