Although the origins of the train concept are to be found in the Middle Ages, and the use of steam power for locomotives emerged in the Industrial Revolution of the 18th century, the train really came of age in the Victorian era of the 19th century. At this time there was an explosion of technical ideas, and this combined with greater national wealth and a rapidly changing social and economic climate to spur a railway boom. Railroad lines spread over every part of the world where there was a social and economic advantage to be gained, and there was an extraordinarily rapid development in the speed and capacity of trains operating on these lines.