LIST OF ILLUSTRATIONS.

Fig. 1. Stigmaria " 2. Annularia radiata " 3. Rhacopteris inaequilatera " 4.  Frond of Pecopteris " 5. Pecopteris Serlii " 6. Sphenopteris affinis " 7. Catamites Suckowii " 8. Calamocladus grandis " 9. Asterophyllites foliosa " 10. Spenophyllum cuneifolium " 11.  Cast of Lepidodendron " 12. Lepidodendron longifolium " 13. Lepidodendron aculeatum " 14. Lepidostrobus " 15. Lycopodites " 16. Stigmaria ficoides " 17.  Section of Stigmaria " 18.  Sigillarian trunks in sandstone " 19. Productus " 20. Encrinite " 21.  Encrinital limestone " 22.  Various encrinites " 23. Cyathophyllum " 24. Archegosaurus minor " 25. Psammodus porosus " 26. Orthoceras " 27. Fenestella retepora " 28. Goniatites " 29. Aviculopecten papyraceus " 30.  Fragment of Lepidodendron " 31.  Engine-house at head of a Coal-Pit " 32.  Gas Jet and Davy Lamp " 33.  Part of a Sigillarian trunk " 34.  Inside a Gas-holder " 35.  Filling Retorts by Machinery " 36.  “Condensers” " 37.  “Washers” " 38.  “Purifiers”

CHAPTER I.

THE ORIGIN OF COAL AND THE PLANTS OF
WHICH IT IS COMPOSED.

From the homely scuttle of coal at the side of the hearth to the gorgeously verdant vegetation of a forest of mammoth trees, might have appeared a somewhat far cry in the eyes of those who lived some fifty years ago.  But there are few now who do not know what was the origin of the coal which they use so freely, and which in obedience to their demand has been brought up more than a thousand feet from the bowels of the earth; and, although familiarity has in a sense bred contempt for that which a few shillings will always purchase, in all probability a stray thought does occasionally cross one’s mind, giving birth to feelings of a more or less thankful nature that such a store of heat and light was long ago laid up in this earth of ours for our use, when as yet man was not destined to put in an appearance for many, many ages to come.  We can scarcely imagine the industrial condition of our country in the absence of so fortunate a supply of coal; and the many good things which are obtained from it, and the uses to which, as we shall see, it can be put, do indeed demand recognition.

Were our present forests uprooted and overthrown, to be covered by sedimentary deposits such as those which cover our coal-seams, the amount of coal which would be thereby formed for use in some future age, would amount to a thickness of perhaps two or three inches at most, and yet, in one coal-field alone, that of Westphalia, the 117 most important seams, if placed one above the other in immediate succession,