Henry had blazed the way for others to work out the principles of the electric motor, and a few experimenters attempted to follow his lead. Thomas Davenport, a blacksmith of Brandon, Vermont, built an electric car in 1835, which he was able to drive on the road, and so made himself the pioneer of the automobile in America. Twelve years later Moses G. Farmer exhibited at various places in New England an electric-driven locomotive, and in 1851 Charles Grafton Page drove an electric car, on the tracks of the Baltimore and Ohio Railroad, from Washington to Bladensburg, at the rate of nineteen miles an hour. But the cost of batteries was too great and the use of the electric motor in transportation not yet practicable. The great principle of the dynamo, or electric generator, was discovered by Faraday and Henry but the process of its development into an agency of practical power consumed many years; and without the dynamo for the generation of power the electric motor had to stand still and there could be no practicable application of electricity to transportation, or manufacturing, or lighting. So it was that, except for the telegraph, whose story is told in another chapter, there was little more American achievement in electricity until after the Civil War. The arc light as a practical illuminating device came in 1878. It was introduced by Charles F. Brush, a young Ohio engineer and graduate of the University of Michigan. Others before him had attacked the problem of electric lighting, but lack of suitable carbons stood in the way of their success. Brush overcame the chief difficulties and made several lamps to burn in series from one dynamo. The first Brush lights used for street illumination were erected in Cleveland, Ohio, and soon the use of arc lights became general. Other inventors improved the apparatus, but still there were drawbacks. For outdoor lighting and for large halls they served the purpose, but they could not be used in small rooms. Besides, they were in series, that is, the current passed through every lamp in turn, and an accident to one threw the whole series out of action. The whole problem of indoor lighting was to be solved by one of America's most famous inventors.