Now the pressure which we can exert by machinery is absolutely nothing compared to the weight of all those hundreds of feet of solid rock which lie over the coal-beds, and which has pressed them down for thousands and perhaps millions of years ; and besides this, we know that parts of the inside of the earth are very hot, and many of the rocks in which coal is found are altered by heat. So we can picture to ourselves that the coal was not only squeezed into a solid mass, but often much of the oil and gas which were in the leaves of the plants was driven out by heat, and the whole baked, as it were, into one substance. The difference between coal which flames and coal which burns only with a red heat, is chiefly that one has been baked and crushed more than the other. Coal which flames has still got in it the tar and the gas and the oils which the plant stored up in its leaves, and these when they escape again give back the sunbeams in a bright flame. The hard stone coal, on the contrary, has lost a great part of these oils, and only carbon remains, which seizes hold of the oxygen of the air and burns without flame. Coke is pure carbon, which we make artificially by driving out the oils and gases from coal, and the gas we burn is part of what is driven out.

We can easily make coal-gas here in this room. I have brought a tobacco-pipe, the bowl of which is filled with a little powdered coal, and the broad end cemented up with Stourbridge clay. When we place this bowl over a spirit-lamp and make it very hot, the gas is driven out at the narrow end of the pipe and lights easily (see Fig. 53). This is the way all our gas is made, only that furnaces are used to bake the coal in, and the gas is passed into large reservoirs till it is wanted for use.

You will find it difficult at first to understand how coal can be so full of oil and tar and gases, until you have tried to think over how much of all these there is in plants, and especially in seeds—-think of the oils oi

almonds, of lavender, of cloves, and of caraways ; and the oils of turpentine which we get from the pines, and out of which tar is made. When you remember these and many more, and also how the seeds of the club-moss now are largely charged wdth oil, you will easily imagine that the large masses of coal-plants which have been pressed together and broken and crushed, would give out a great deal of oil which, when made very hot, rises up as gas. You may often yourself see tar oozing out of the lumps of coal in a fire, and making little black bubbles which burst and burn. It is from this tar that James Young first made the paraffin oil we burn in our lamps, and the spirit benzoline comes from the same source.

From benzoline, again, we get a liquid called aniline, from which are made so many of our beautiful dyes — mauve, magenta, and violet ; and what is still more curious, the bitter almonds, pear-drops, and many othei sweets which children like so well, are actually flavoured by essences which come out of coal-tar. Thus from coal we get not only nearly all our heat and our light, but beautiful colours and pleasant flavours. We spoke just now of the plants of the coal as being without beautiful flowers, and yet we see that long, long after their death they give us lovely colours and tints as beautiful as any in flower-world now.

Think, then, how much we owe to these plants which lived and died so long ago ! If they had been able to reason, perhaps they might have said that they did not seem of much use in the world. They had no pretty flowers, and there was no one to admire their beautiful green foliage except a few croaking reptiles, and little crickets and grasshoppers; and they lived and died all on one spot, generation after generation, without seeming to do much good to anything or anybody. Then they were covered up and put out of sight, and down in the dark earth they were pressed all out of shape and lost their beauty and became only black, hard coal. There they lay for centuries and centuries, and thousands and thousands of years, and still no one seemed to want them.

At last, one day, long, long after man had been living on the earth, and had been burning wood for fires, and so gradually using up the trees in the forests, it was discovered that this black stone would burn, and from that time coal has been becoming every day more and more useful. Without it not only should we have been without warmth in our houses, or light in our streets when the stock of forest-wood was used up ; but we could never have melted large quantities of iron-stone and extracted the iron. We have proof of this in Sussex. The whole country is full of ironstone, and the railings of St. Paul's churchyard are made of Sussex iron. Iron-foundries were at work there as long as there was wood enough to supply them, but gradually the w^orks fell into disuse, and the last furnace was put out in the year 1809. So now, because there is no coal in Sussex, the iron lies idle; while in the North, where the ironstone is near the coal-mines, hundreds of tons are melted out every day.

Again, without coal we could have had no engines of any kind, and consequently no large manufactories of cotton goods, linen goods, or cutlery. In fact, almost everything we use could only have been made with difficulty and in small quantities ; and even if we could have made them it would have been impossible to have sent them so quickly all over the world without coal, for we could have had no railways or steamships, but must have carried all goods along canals, and by slow sailing vessels. We ourselves must have taken days to perform journeys now made in a few hours, and months to reach our colonies.

In consequence of this we should have remained a very poor people. Without manufactories and industries we sliould have had to live chiefly by tilling the ground, and everyone being obliged to toil foi ig2

their daily bread, there would have been much less time or opportunity for anyone to study science, or literature, or history, or to provide themselves with comforts and refinements of life.

All this then, those plants and trees of the far-ofl ages, which seemed to lead such useless lives, have Jone and are doing for us. There are many people in the world who complain that life is dull, that they do not see the use of it, and that there seems no work specially for them to do. I would advise such people, whether they are grown up or little children, to read the story of the plants which form the coal. These saw no results during their own short existences, they only lived and enjoyed the bright sunshine, and did their work, and were content. And now thousands, probably millions, of years after they lived and died, England owes her greatness, and we much of our happiness and comfort, to the sunbeams which those plants wove into their lives.

They burst forth again in our fires, in our brilliant lights, and in our engines, and do the greater part ol our work; teaching us *• 'I hat nothing walks with aimless feet, 'I hat not one life shall be destroyed, Or cast as rubbish to the void, When God hath made the pile complete." In Mt-moriam^ Ut,

Lecture IX. Bees in the Hive

I am going to ask you to visit with me to-day one of the most wonderful cities in the world. It is a city with no human beings in it, and yet it is densely populated, for such a city may contain from twenty thousand to sixty thousand inhabitants. In it you will find streets, but no pavements, for the inhabitants walk along

the walls of the houses ; while in the houses you will see no windows, for each house just fits its owner, and the door is the only opening in it. Though made without hands these houses are most evenly and regularly built in tiers one above the other ; and here and there a few royal palaces, larger and more spacious than the rest, catch the eye conspicuously as they stand out at the corners of the streets.

Some of the ordinary houses are used to live in, wl ile others serve as storehouses where food is laid up in the summer to feed the inhabitants during the winter, when they are not allowed to go outside the walls. Not that the gates are ever shut : that is not necessary, for in this wonderful city each citizen follows the laws ; going out when it is time to go out, coming home at proper hours, and staying at home when it is his or her duty. And in the winter, when it is very cold outside, the inhabitants, having no fires, keep themselves warm within the city by clustering together, and never venturing out of doors.

One single queen reigns over the whole of this numerous population, and you might perhaps fancy that, having so many subjects to work for her and wait upon her, she would do nothing but amuse herself. On the contrary, she too obeys the laws laid down for her guidance, and never, except on one or two state occasions, goes out of the city, but works as hard as the rest in performing her own royal duties.

From sunrise to sunset, whenever thq weather is fine, all is life, activity, and bustle in this busy city Though the gates are so narrow that two inhabitants can only just pass each other on their way through them, yet thousands go in and out every hour of the day ; some bringing in materials to build new houses, others food and provisions to store up for the winter and while all appears confusion and disorder among this rapidly moving throng, yet in reality each has her own work to do, and perfect order reigns over the whole.

Even if you did not already know from the title of the lecture what city this is that I am describing, you would no doubt guess that it is a beehive. For where in the whole world, except indeed upon an anthill, can we find so busy, so industrious, or so orderly a community as among the bees } More than a hundred years ago, a blind naturalist, Francois Huber, set himself to stud}^ the habits of these wonderful insects, and with the help of his wife and an intelligent manservant managed to learn most of their secrets. Before his time all naturalists had failed in watching bees, because if they put them in hives with glass windows, the bees, not liking the light, closed up the windows with cement before they began to work. But Huber invented a hive which he could open and close at will, putting a glass hive inside it, and by this means he was able to surprise the bees at their work. Thanks to his studies, and to those of other naturalists who have followed in his steps, we now know almost as much about the home of bees as we do about our own ; and if we follow out to-day the building of a bee-city and the life of its inhabitants, I think you will acknowledge that they are a wonderful community, and that it is a great compliment to anyone to say that he 01 she is " as busy as a bee."

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