The slate-pit, in which this bone was found, is about a quarter of a mile north-west from Stonesfield, upon the declivity of a rising ground, the upper stratum of which is a vegetable mould about eight or ten inches thick: under this is a bed of rubble, with a mixture of sand and clay, very coarse, about six feet deep, in which are a great number of anomiæ both plain and striated, and many small oblong oysters, which the workmen call the sickle-oyster, some of them being found crooked, and bearing some resemblance to that instrument; but all differing from the curvi-rostra[19] of Moreton.
Immediately under this stratum of rubble is a bed of soft grey stone, of no use; but containing the echini ovarii, with great mamillæ, the clypeati of different sizes, all well preserved; and also many anomiæ and pectines. This bed, which is about seven or eight feet in depth, lies immediately above the stratum of stone, in which the bone was found.
This stratum is never wrought by the workmen, being arenarious, and too soft for their use. It is about four or five feet thick, and forms a kind of roof to them, as they dig out the stone, of which the slates are formed; for they work these pits in the same manner as they do the coal-pits, leaving pillars at proper distances to keep their roof from falling in.
This last bed of slate-stone is about five feet depth, and lower than this they never dig. So that the whole depth of the pit amounts to about 24 or 25 feet.
It was by working out the slate-stone, that this bone was discovered sticking to the roof of the pit, where the men were pursuing their work; and with a great deal of caution, and no less pains, they got it down intire, but attached to a large piece of stone; and in this state it now remains in my possession.
There is no water in the works, but such as descends from the surface thro’ perpendicular fissures; and the whole is spent in forming the stalactites and stalagmites, of which there is great variety, and whose dimensions are constantly increasing. One of the workmen has been so curious, as to mark the time of the growth of some of them for several years past.
I am, with the greatest esteem,
Dear Sir,
Your ever obedient,
and most humble Servant,
Joshua Platt.
Oxon, Jan. 20. 1758.