But we have the advantage over our shovel-headed predecessor—­or possibly ancestor—­and can perceive that a certain vein of thrift runs through this apparent prodigality.  Nature is never in a hurry, and seems to have had always before her eyes the adage, “Keep a thing long enough, and you will find a use for it.”  She has kept her beds of coal many millions of years without being able to find much use for them; she has sent them down beneath the sea, and the sea-beasts could make nothing of them; she has raised them up into dry land, and laid the black veins bare, and still, for ages and ages, there was no living thing on the face of the earth that could see any sort of value in them; and it was only the other day, so to speak, that she turned a new creature out of her workshop, who by degrees acquired sufficient wits to make a fire, and then to discover that the black rock would burn.

I suppose that nineteen hundred years ago, when Julius Caesar was good enough to deal with Britain as we have dealt with New Zealand, the primaeval Briton, blue with cold and woad, may have known that the strange black stone, of which he found lumps here and there in his wanderings, would burn, and so help to warm his body and cook his food.  Saxon, Dane, and Norman swarmed into the land.  The English people grew into a powerful nation, and Nature still waited for a full return of the capital she had invested in the ancient club-mosses.  The eighteenth century arrived, and with it James Watt.  The brain of that man was the spore out of which was developed the modern steam-engine, and all the prodigious trees and branches of modern industry which have grown out of this.  But coal is as much an essential condition of this growth and development as carbonic acid is for that of a club-moss.  Wanting coal, we could not have smelted the iron needed to make our engines, nor have worked our engines when we had got them.  But take away the engines, and the great towns of Yorkshire and Lancashire vanish like a dream.  Manufactures give place to agriculture and pasture, and not ten men can live where now ten thousand are amply supported.

Thus, all this abundant wealth of money and of vivid life is Nature’s interest upon her investment in club-mosses, and the like, so long ago.  But what becomes of the coal which is burnt in yielding this interest?  Heat comes out of it, light comes out of it; and if we could gather together all that goes up the chimney, and all that remains in the grate of a thoroughly-burnt coal-fire, we should find ourselves in possession of a quantity of carbonic acid, water, ammonia, and mineral matters, exactly equal in weight to the coal.  But these are the very matters with which Nature supplied the club-mosses which made the coal She is paid back principal and interest at the same time; and she straightway invests the carbonic acid, the water, and the ammonia in new forms of life, feeding with them the plants that now live.  Thrifty Nature!  Surely no prodigal, but most notable of housekeepers!