One of the greatest of unknown men of genius was the inventor of the wheel. Probably—as in the case of most inventions—he shares the credit with others who prepared the way for him by discovering that heavy weights could be more easily rolled than dragged. But, whatever the origin of the wheel and axle, the combination was so admirable that it remained unchanged in its essential features for centuries and still forms the primary element in locomotion.

Some of the earliest forms of vehicle can be found co-existing with the very latest. In Oporto, for instance, there are electric tramways, but there are also ox wagons which seem to belong to the childhood of the world. The wheels are rigidly fixed to rotating axles (the oldest known arrangement) and the supports of both the front and the back axles are rigidly fixed to the wagon. The result is that the vehicle cannot 'steer' and must be dragged round corners. Some time ago the authorities, realising at last that this dragging was ruinous to the road surfaces, made a regulation that all wagons should have their front axles pivoted. This attempt at improvement caused more agitation than the Revolution itself. The owners of wagons argued—with perfect justice—that the rigid wagon had served for innumerable generations; and they refused, in the face of fines, to make the change. Their resistance was so general and so dogged that the law became a dead letter, and the people reverted with great content to the ancient system which divided the business of local transport between yoked oxen and women who had been trained from girlhood to carry heavy loads upon their heads.

This example of conservatism, though extreme, is characteristic of the attitude of the general public towards innovations in locomotion. Until mechanical power came to be used, there was—for many centuries—nothing which could be described as a radical innovation in transport. Roads were multiplied and improved; some advance was made in the design and construction of carriages; and the organisation of posting and stage-coach services was developed. But little more was done. Compared with these superficial changes, the idea of using steam power on the highway or on a railroad was so drastic a change that it roused tremendous opposition. The railway companies fought this opposition and overcame it, but the use of steam carriages on ordinary roads was postponed until the appearance of the petrol motor encouraged a movement—once more against strong prejudice—for the repeal of the legislation which restricted the use of mechanically-propelled vehicles on the roads. In a similar way horse tramways were violently attacked; and their conversion to electric traction was opposed by a determined minority in every town. More recently, there was a vigorous agitation against the substitution of motor omnibuses for horse omnibuses in London and elsewhere.

To some extent this recurrent opposition was reasonable enough. The new forms of locomotion had dangers of their own; they were generally noisy and sometimes dirty; and occasionally, as in the case of early tramways, they were a nuisance to existing traffic. But it may be noted that electricity claims to provide a means of locomotion not only more rapid and more efficient (in most cases) than any other, but free from many of the drawbacks which gave conservatism an excuse for opposing the introduction of steam and other forms of locomotion.

In the following pages I hope to give a clear account of the achievements of electricity in the field of locomotion and also to indicate some of its more immediate potentialities.