But all these and other fantastic devices never got beyond the experimental stage, and nothing of a substantial, practical character was ever evolved from them. It remained for the latter part of the eighteenth century to see the subject taken up seriously and considered in a way that promised definite results. And it was steam that then brought the matter strongly to the front.
It is true that Sir Isaac Newton tentatively suggested the possibility of carriage propulsion by steam about 1680, but his suggestion lay dormant for nearly a century. Then the growing knowledge of the power of steam and the possibilities in the new element turned men's thoughts again very forcibly to this theme. The stationary engine had shown its usefulness, and the consideration of making this stationary machine movable, and therefore available for transportation, naturally followed.
Dr. Erasmus Darwin is said to have urged James Watt and Matthew Boulton to build a fiery chariot as early as 1765. In his poem, The Botanic Garden, famous in that day, Dr. Darwin, like a prophet crying in the wilderness, sang of the future of steam in these lines:
"Soon shall thy arm, unconquered steam, afar Drag the slow barge, or drive the rapid car; On, on wide waving wings, expanded bear The flying chariot through the field of air; Fair crews triumphant, leaning from above, Shall wave their fluttering 'kerchiefs as they move, Or warrior bands alarm the gaping crowds, And armies shrink beneath the shadowy clouds."
These lines may indeed be fairly interpreted as anticipating in prophetic prediction the modern motor airship, as well as the motor car.
It was considerably later than this that the dream of Dr. Darwin approached to realization at the hands of the steam engine inventors and builders. Aside from Nicholas Joseph Cugnot, the French army officer who, about 1769, constructed an artillery wagon propelled by a high-pressure engine, those who first built successful self-propelled vehicles for highway travel were the famous engineers of England and Scotland, who harnessed steam and developed the high-pressure engine in the last half of the eighteenth century and the first half of the nineteenth. James Watt patented, in 1782, a double-acting engine, which he planned might be "applied to give motion to wheel carriages," the engine to be portable; but he never put the patent to trial. He was followed by George Stephenson, Richard Trevithick, Walter Hancock, Goldsworthy Gurney, David Gordon, William Brunton and others in England, and Oliver Evans, Nathan Read and Thomas Blanchard in the United States, with two score or more contemporaries. For more than half a century steam vehicles of various types were invented by these engineers and many of them were brought into practical use.