As time ran its appointed course we got a bit used to the bikes, and, finding that you cannot ride all day and all night, we began to look at the books. Only one of them comes into this story. It was called 'The Youth's Manual of Scientific and Mechanical Recreation,' and, of course, we none of us read it till we'd read everything else, and then we found it wasn't half bad. It taught you how to make all sorts of things--galvanic batteries, and kites, and mouse-traps, and how to electroplate things, and how to do wood-carving and leather-work. We tried as many of the things as we had money for, and some of them succeeded. Then we made a fire-balloon. It took a long time to make, and then it caught fire and blazed away before we could get it launched. So we made another, and Noel dropped it near the water-butt, where there was a puddle, and, being tissue-paper, it was unable to stand the strain. So we made another. But the paste was bad, and it did not stick. So we made another. Then, at last, when all was ready, Oswald climbed on to the pigsty at Mrs. Beales', and held the balloon very steady while Dicky lighted the cotton-wool, soaked in spirits of wine, which hangs from the end (where cars are in larger sizes), and causes it to be called a fire-balloon. A taper is burned inside the balloon, and then, according to the book, 'it readily ascends, and is carried away by the wind, sometimes to a considerable distance.' Well, this time everything happened just as the book said, which is not always the case. It was a clear, dark night, bright stars only. And, to our relief and agreeable surprise, our balloon rose up and sailed away, dragging its lighted tail like a home-made comet. It sailed away over the marshes, getting smaller and smaller, and at last it was, though lost to sight, to memory dear. Some of us thought it wasn't worth doing, but Oswald was glad he had persevered. He does hate to be beaten. However, we none of us cared to make another, so we went to bed. Dicky always goes to sleep directly on these occasions, but Oswald, more thoughtful for his years, sometimes reviews the events of the day. He must have been nearly asleep, because he was just reviewing an elephant that flew with a lamp inside, so that it looked like a fire-balloon, when Alice suddenly came and woke him up completely. 'Beware!' she said in tones of awe. And he said, but not crossly: 'Well, what on earth's up now?' 'The fire-balloon!' replied Alice. 'What about it?' he rejoined, still calm and kind, though roused from his reviews. 'Why, it came to me all in a minute! Oh, Oswald--when it comes down--there are lots of farms in the march. Suppose it comes down and sets light to something! It's a crime--arsenic or something--and you can be hanged for it!' 'Don't be an idiot!' said Oswald kindly. 'The book wouldn't have told youths how to make them if they were crimes. Go back to bed, for goodness' sake!' 'I wish we hadn't--oh, I do!' said Alice.