"We remove a scale from the rock, and behind is
still another picture. The whole mass of the shaly roof is a portfolio of inimitable sketches. The sharpest outlines and the minutest serratures are clearly traced. Buds, woody stems, cones, fruits, grasses, rushes, club mosses, all are by turns pictured on the dusky ceiling."
In another portion of his book, Professor Winchell speaks of very curious things that have been found in many instances by miners in the heart of a coal mine.
These are the trunks of trees, which are found standing upright as though still growing.
Mr. Winchell says:
"These tree-trunks are from one to five feet in diameter, and are sometimes sixty or seventy feet in height.
"In many instances they have been found standing erect, and have evidently been buried by accumulations of mud and sand.
"In the excavation of a bed of coal these petrified trees are not unfrequently cut off below, when the slight taper of the trunk permits them to slide down into the mine.
"These 'coal pipes' are much dreaded by English miners, for almost every year they are the cause of fatal accidents."