There were tall grasses, ferns, lycopods, besides sigillaria, asterophyllites, now scarce plants, but then the species might be counted by thousands.
The coal measures owe their origin to this period of profuse vegetation.

The yet elastic and yielding crust of the earth obeyed the fluid forces beneath.

Thence innumerable fissures and depressions.

The plants, sunk underneath the waters, formed by degrees into vast accumulated masses.
Then came the chemical action of nature; in the depths of the seas the vegetable accumulations first became peat; then, acted upon by generated gases and the heat of fermentation, they underwent a process of complete mineralization.
Thus were formed those immense coalfields, which nevertheless, are not inexhaustible, and which three centuries at the present accelerated rate of consumption will exhaust unless the industrial world will devise a remedy.
These reflections came into my mind whilst I was contemplating the mineral wealth stored up in this portion of the globe.

These no doubt, I thought, will never be discovered; the working of such deep mines would involve too large an outlay, and where would be the use as long as coal is yet spread far and wide near the surface?
Such as my eyes behold these virgin stores, such they will be when this world comes to an end.
But still we marched on, and I alone was forgetting the length of the way by losing myself in the midst of geological contemplations.