The Antient and Present State of the County and City of Cork 1: 156-157 (1750)

Robertus Berkley, D.D.
26 Martii, 1748

Burnt Clay

At Middletown there are veins of several coloured marbles, particularly liver coloured, black, and grey, but that of Castlemartyr of the grey kind exceeds it in closeness of texture and largeness of blocks. There are few woods in this barony, except those of Killeigh and Glanbowre, in the latter are some good echoes, affording 7 or 8 repercussions from the same sound. The hills to the north are but poor and very stony, the manure mostly used is sea-sand. Burning and grassing has been too much practiced, to the great impoverishment of the soil. A new kind of manure used in some other parts of this county of late, is burnt clay. The kiln for this purpose is thus contrived.

The kiln is 12 feet wide, and 24 long in the clear, the walls are built of fresh sods, 3 feet high to batter inwards. A A are partition walls at 4 feet distance, which are to burn more equally at first. B B are small trenches dug through each division, about 6 inches wide and 10 deep, which are to be covered with flat stones in such a manner, as to hinder the trench from being choaked, and yet to give air to the fewel. Any clay may serve to burn for manure, but the stiffest clay produces the most and best ashes. Before the kiln is built, 40 or 50 barrels of clay are to be spread on the ground like turf to dry, next 800 faggots of furze are to be provided. All things being ready, the walls are to be built of fresh sods, leaving the side farthest from the wind open, until the fewel and clay are laid, and until each division is lighted up, and leaving that which is farthest from the wind to the last. Then, the wall of each apartment is to be built up as they are fired. The faggots must be well trodden and some turf and billets laid over them, and lastly, the clay must be laid on about 4 inches thick, even with the walls. If you begin in March to dig your clay, the kiln may be kept burning all the summer, raising the walls as it fires, but it must be well attended at first, to keep the fire from breaking out, by constantly covering it with dry clay. When it is well lighted up, wet clay may be laid on; if the clay be laid conveniently near the kiln, one may will be sufficient to attend it morning and evening for an hour at a time. Too much laid on at a time, or too close, may put out the fire, both which are carefully to be avoided. Thirty or 40 barrels of these ashes will suffice for an English acre, and is good both for corn and grass.