Before we leave our good friend the scientist and his young companion, let us go over a few more of the things about which they talked. To take up all of them would be to prolong this book indefinitely, for the boy's mind was ever unfolding to the new things of the world and with each subject mastered, or at least partially understood, he was anxious to go on to the next. Not that he did not have his special hobbies upon which he spent most of his time, for he did, but that did not prevent his inquiring young mind from reaching out for new and more wonderful things once he had come to realize the world of marvels in which we live. One of this youth's favourite pastimes was photography, and as an amateur his work had attracted considerable attention from his friends. One day in the summer, when all the trees, shrubs, and flowers were at the height of their beauty, he came into the laboratory where his scientific friend was working over an experiment. "I have heard of a process of colour photography," he said, "and I wonder if I couldn't make use of it to get some good pictures out in the country, showing just exactly how it is." "Certainly," replied his friend. "There are a number of systems of colour photography now--all invented within the last few years. None of them is perfect though, and you would have the added fun of carrying on some experiments that might bring to light some valuable knowledge. "While it is possible to make coloured photographic prints now, by means of a specially treated paper, colour photography is best known as a means of making beautiful transparent glass plates and lantern slides. When held up to the light, the transparencies give an accurate picture of the scene in natural colours. The paper I mention can be bought at the photographic houses, but the inventors do not claim yet that their process is so perfect as to give exact reproductions of all the shades of colours unless they are well defined in the positive plates. The prints are made from the positive transparencies in just the same way that photographic prints are made from black and white photographic plates." "Let's try some colour photographs," promptly said the boy. "Will you go out into the country with me some Saturday and help me?" "I certainly will be glad to go with you, but you are a better photographer than I am, for you see, about the only kind of photography I do now is with a microscope, such as you have looked through here many times. Your own regular camera and tripod will be all you will need, for I will buy the colour plates upon which the pictures are to be taken." They made their trip to the country on the first pleasant Saturday, and while they were out the scientist explained many points about the system.