Wales, p. 450.) There can be no doubt, however, about the fact that in one shaft a great thickness of toadstone was met with, though whether it was got through is perhaps doubtful. Farey (op. cit. p. 274) considered that a sudden outburst of water, which took place at the bottom of the shaft, indicated that the underlying limestone had been touched, but it is generally believed that the toadstone was not bottomed. It may be mentioned here that the toadstone contained many fragments of limestone, differing scarcely at all in appearance from the parent rock. Specimens abound in the hillock.

Near Tideswell the sequence of beds is as follows:- *

66

At Great Hucklow there are two mines at work, one of which by the order of Mr. Moore of Bamford was kindly thrown open to us.† The lode runs nearly east and west. A section across the lower part is given in fig. 32. It is a rent 50 yards across at the surface, but narrowing down to 10 yards at a depth of 66 fathoms, filled in with spar or 'kebble," chiefly calcite, but a little heavy spar also occurs. Embedded in the "kebble" lie many large detached blocks or "horses" of limestone and toadstone. Through this broad vein there run narrow, irregular strings of galena, two of which, one near the north and another near the south wall, can be worked with profit; here and there a third vein has been worked between the two. The lode is a fault with a downthrow to the north, and at this mine the throw was about 12 fathoms. In the 60-fathom level a clay-parting or "clay-joint " a few inches thick was crossed, blue in the upper half and brown below; it was not unlike decomposed toadstone. There is said to be a second "clay-joint" below this.

The top of the toadstone is reached on the south side of the lode at a depth of 62 fathoms, and we were told that the 60-fathom level had been driven to the west beyond the point where they ought to have struck the toadstone, if it had the same dip as the limestone, but that they had not yet met with it. If this be really the case, and if, as there is every reason to think, the toadstone is an interbedded igneous rock, either it must thin out very rapidly to the west, or there must be some cross fault of which the miners are not aware.

In the 66-fathom level they were working the vein of galena on the south side; it was only an inch thick, but on the day before our visit it had been five inches thick, and it sometimes widens out to three feet. It is interesting to note that here, where the wall is toadstone, the string of galena lies at some distance from it, while higher up, where the wall was limestone, the vein bore best close to the southern cheek. It is also worth notice that whereas in the upper part of the lode the "horses" were all limestone, we find here in the neighbourhood of the toadstone wall "horses " of decomposed clayey toadstone.

At the 75-fathom level both walls of the lode are toadstone, but till the workings have been pushed on farther it is impossible to say how the vein will bear here.

* As given by Mr. J. Hancock of Tideswell.

†These notes, with the accompanying figure 31, are taken from the 1st edition of this Memoir, published in 1869.

The toadstone is an amygdaloidal rock, as is very beautifully shown where it has decomposed into a soft friable clay. For by washing this, or merely rubbing it between the hands, one may pick out the small rounded or almond-shaped kernels of calcite, which once filled the cavities in the vesicular rock. These pieces of calcite are coated with a green mineral (probably delessite), and the rock thus acquires a speckled look, showing green spots on a yellowish brown ground.

Fig. 32.

Section across a part of the Lode at Great Hucklow.

3. Lode filled with "kebble," and "horses" of limestone and toadstone; the black lines represent strings of galena.

the Milldam Mine the lode passes

It will be seen by the map that at the boundary of the Yoredale Shale. The Pumping Engine Shaft proved the following section :-*

At the Smithy Coe Shaft, 250 yards further east, the shale extended to 24 fathoms depth, and in Shuttleworth's Shaft to 50 fathoms, the total depth of working being 82 fathoms. There the vein runs nearly along the strike of the beds, and the depth to the limestone in the Silence Shaft (1,200 yards east of Milldam) was 54 fathoms 4 feet, the shaft being carried 33 fathoms further in limestone. The most productive ground was found generally at 25 to 40 fathoms below the base of the Yoredale Shale.

A little west of the Smithy Coe Shaft the vein throws off a branch on the south known as the Sun vein; the two are believed to unite again further east. Near the New Edge Mine a branch was thrown off on the north

*For the information concerning these mines I am indebted to Mr. Leonard Maltby of Great Hucklow,

side, which ran to Little Milldam Shaft, and the ownership of which was long disputed.

One hundred yards east of the Silence Mine is the Old Grove Shaft, near which a vein branches off in north-westerly direction. It has been worked at the head of Bretton Clough in the Back o' the Edge Mine, and in a level, known as May Sough, on the west side of the grit hill.

The succeeding mines are the New Grove, Slater's, Black Engine, and Middleton, all of which have been long disused. At the last named the vein divides again, one branch running south of east through the Old Twelve Meers Mine, the other more nearly east through Twelve Meers, Broadlow, Lady Wash, and New Engine Mines. In 1746, after a great lawsuit, during which much evidence as to the character of the veins was taken, it was decided that the more northerly of the two was the continuation of the great Hucklow Vein, one of the points being that it underlay south. The Hucklow Vein underlies south at the Silence Mine also; there would appear, therefore, to be a change in the direction of the hade between this mine and Milldam (see also p. 55).

The Broadlow Mine has been long abandoned, but the Lady Wash and the New Engine shafts have been worked more recently. Both were started in the grit, and sunk through into the limestone; the former, which was 156 fathoms deep, reached the limestone at 132 fathoms 4 feet (p. 57). In sinking through the shale, the bed described subsequently (p. 164), as containing rock-oil, was encountered. The oil occurred in bands of a honeycombed but intensely hard rock, resembling melted iron, and about six to eight inches thick; the rock was known as "cauk " (? coke).

This part of the vein is unwatered by Stoke Sough, a level driven from the Derwent 500 yards north of Stoke Hall, for a distance of about 14 miles, at a cost of 35,000l. (Farey, op. cit. vol. 1, p. 330). The depth to the sough at the New Engine is 131 fathoms; the mine, which had been abandoned after slightly exceeding this depth, was carried, by the help of improved pumping machinery to the greater depth stated about the year 1860. The sough is said to terminate at Lady Wash. In Eyam Registry there are records of men having been killed in Stoke Sough in the years 1732, 1734, and 1778, probably through explosions of fire-damp (Farey, op. cit. p. 333). The water from this sough was warm (Ib. p. 505).

The Black Hole Vein runs a little south of west from Highcliffe to the great chasm known as Waterfall. It was worked in the Black Hole, and the Little Pasture Mines, at the latter to a depth of 42 fathoms.* At Waterfall it intersects the Cross Low Vein, which runs through Foolow to the west, and to Dustypit Mine to the east. At Dustypit the Cross Low Vein divides into three; the Dustypit vein,† a close hard and black vein, on the north; the Cross Low, a soft, "sludgy" vein

*As I was informed by Mr. J. Hancock of Tideswell. A level was driven along the top of the limestone from this mine at 30 fathoms depth to Twelve Meers. Fluorspar occurred in Little Pasture Mine.

†This vein runs to the Highcliffe Mine, where a curious phenomenon was observed. The vein was traversed by divisional planes, parallel to the walls, and polished and grooved in the manner known as "slickenside." On being struck or even scratched by a pick a crackling noise was heard, and was after a short pause followed by an explosion, often most violent in its effects. A great explosion is described by Whitehurst (Formation of the Earth) as having occurred in 1738, and the phenomenon is referred to by nearly all writers on Derbyshire in the last century. It appears even that the mine was abandoned for a time on account of the danger, but that the miners subsequently learnt how to take advantage of the peculiarity in getting the ore. Such explosions, as I am informed by Mr. Maltby, are still liable to occur on a smaller scale in the neighbouring mines;

with caulk, in the centre, and a vein with fluorspar, and very rich in ore, on the south. At the Dustypit shaft the following section was proved :

The vein was worked for some 300 or 400 yards in a south-easterly direction, and proved extremely profitable. The ore, which lay in two ribs, and was worked at small expense, occurred above the toadstone, and from 30 to 40 fathoms below the top of the limestone. The vein was impoverished in the immediate neighbourhood of the toadstone.

A little blende was seen in Lady Wash Mine, but with this exception zinc-ores have proved very scarce throughout this neighbourhood.

The mines in Eyam were drained by the Moorwood Sough, which runs from Middleton Hall through the Cliff Stile Mine, and under Eyam (150 yards east of the church), to a point about 400 yards short of the Highcliffe Mine. It appears to have been commenced about 1750, but twice abandoned before reaching the point stated.

The Watergrove Mine was on a very heavily watered pipe-vein, near Wardlow Mires. It was abandoned about the year 1850. The run of the pipe is said to have been extremely irregular, both in depth and direction. The mine was drained to a depth of about 45 fathoms by a level opening into Middleton Dale, about a mile above Middleton. An outlier of Yoredale Shale occurs at Watergrove, proving the limestone to be the top bed; the beds undulate considerably, as may be seen on the surface.

On Middleton Moor there are many old workings, chiefly along the Cliff Stile Rake, which runs about W. 20° S., and a cross vein running about south-east. The mines have been long abandoned except by hillockers in search of caulk.

The Seedlow Rake runs nearly east and west through Wardlow; west of this village, it takes the name of the Sough Vein, presumably through the existence of a sough into Cressbrook Dale.

Calver Sough is driven from the dam of Calver Mill north-westwards; the engine shaft upon it was sunk to a depth of 25 fathoms and abandoned.

Longstone Edge.

The master-vein of this tract is known as the High Rake and the Deep Rake (or Longstone Edge Vein) in its west and east ranges respectively. At its west end it crosses Cressbrook Dale, but can be better seen in the spar-workings on the road from Monsal Dale. It runs nearly due east with a hade to the north, and is double, with much white calc-spar, and having the appearance of a strong fault. It may be traced thence by old workings for about a mile and a half to a point where it bends to the north-east, and takes the name of the High Rake;

they may be attributed to the mineral (chiefly barytes) being under pressure. The removal of support from one side of a vertical sheet of spar bounded by two planes of slickenside leaves such a sheet in a condition to fly to pieces at the slightest shock (see also p. 128, Odin Mine, and p. 150, footnote, Gang Mine; and A. Strahan, On Explosive Slicken sides, Geol. Mag., dec iii., vol. iv., 1887, p. 460).

here it is being worked for caulk. Resuming its easterly course it becomes the Deep Rake, and has been worked by means of a level driven into it from the Sallet Hole Mine,* in Combs Dale. Toadstone was found at 60 fathoms depth, and was cut into for 10 fathoms to reach the depth at which the level entered the vein. The rake was in many places 14 yards in width, as it must also have been on the surface, judging from the great size of the old open workings along all this part of its course. Caulk was abundant and fluorspar may still be seen adhering to the walls. Further east the limestone forming the walls of the vein has been highly silicified and is being worked for chert (p. 166).

The Crossdale Head Mine is situated about 70 yards south of this vein near its west end, and between it and a vein running south of east along the slope of the hill, also a fault with a down-throw north. The shaft was about 60 fathoms deep and reached the toadstone; the veins are said to be cut out down to this rock. The south-easterly vein divides into two further east, one branch running along the brow of the hill to the Hard Shaft (which was sunk to the toadstone at 50 fathoms depth), the Hard Piece Mine, the White Coe Mine (50 fathoms), and so into the Deep Rake; the other branch known as the Ox Pasture Vein, ranging into the low ground through the Ash Nursery Mine, (between 40 and 50 fathoms), the Ox Pasture Mine (30 fathoms), and the Blue Bell Mine (40 fathoms), east of which it becomes the Tor Vein, which was worked in the Waterhole Mine (sunk to 40 fathoms without touching the toadstone), and in the White Coe Mine.

The Harrybecca, Brightside, Backdale, North Cliff Sough, and Red Rake mines have been worked upon a series of rakes and scrins which run down the hill-side in a general easterly direction towards the Yoredale Shale. The Harrybecca Mine was about 40 fathoms deep, on some scrins which may be seen in old open workings 200 yards to the west. The Brightside Mine was 51 fathoms deep and was drained to a depth of 40 fathoms by a sough opening in Calver village. It was worked upon a great number of scrins, ranging from two to three inches in width and sometimes filled with solid galena. The scrins were divided into "plumbs" and "hadings," the former being vertical joints, the latter apparently partings between beds of limestone, which here dip south-east at about 45.°t The greatest yield in one year was 511 tons. The Backdale Mine was on a southern branch of the Deep Rake. The vein was reached by a cross-cut driven about 100 yards into the hill from the bottom of the shaft, at 40 fathoms depth. The toadstone, rising with the beds, was touched in the north end of the crosscut. The hillock is now being turned over for fluorspar. The North Cliff Sough was driven into the hill-side in a westerly direction in the year 1853. Here also fluorspar is being picked out of the hillock. The Red Rake is a stronger vein branching from the Deep Rake on its north side. It was worked in the Muse Mine and in the Red Rake Mine, which was 20 fathoms deep, with a level of about 50 yards length northwards to the vein. The old workings in the vein above this mine are open, and fluorspar is being cut out of them. The walls show the flutings of slickenside running down eastwards at 20°. South of this vein are some north and south joints, which have been superficially explored by the "old man.”

For my information on this and the succeeding mines I am indebted to Mr. William Bland, of Eyam.

†The dip on the top of the hill is about 10°, but becomes steeper towards the Yoredale Shale, as is often the case.