In the Oxford Museum is a fragment of a remarkable calcareous deposit; it was taken from the pipe which carries off the drain water from a certain colliery in the north of England, and consists of carbonate of lime deposited on the sides of the pipe. The stone is not of one uniform colour; but is striped with alternate layers of black and white, yet both equally carbonate of lime. This has come about in the following way: When the colliers were at work the coal dust naturally blackened the water; which, running through the drain pipe, of course deposited a black mark. When no work was going on the water was necessarily clean, and a white layer was formed. After a time the concretion completely filled up the pipe, and it was taken up; the black and white marks being observed, they were compared with the clerk’s day book, and were found accurately to correspond with the entries therein; namely, small streaks, alternately black and white, represented a week; for during the day the men were working, and during the night, they were at rest. Then came a white layer as large as a black and white one put together. This was Sunday - during which there being no work, the water was clean for forty-eight hours. By and by there appeared a forty-eight hour mark in the middle of one week. The books tell the tale: this was the day when a cock fight took place in the neighbourhood, and all the colliers went by permission to it. In another part of the stone is seen a still larger white mark, namely Christmas Day. It came on a Monday, and all Sunday and Monday the water was clear. Thus the workmen unconsciously recorded, literally in black and white, their times of work and of rest. They justly gave to this specimen the name of “The Sunday Stone”.
Frank Buckland in “Curiosities of Natural History” (1886)
Jim Kennedy, Director