This he evinced by showing to his wondering school companions the model of
a section of the Girvan road, extending from Maybole to Kirkoswald, which
he had executed during his half-holidays.
In consequence of the impoverished circumstances of his father, and being a younger son, John found that he must begin betimes to shift for himself. He therefore left Scotland for New York, where he had an uncle, Dr. William Macadam, by whom he was kindly received, and adopted as a son. He had only reached the age of fifteen when he was thus thrown upon the world; but he appears to have had his full share of that spirit that carries his countrymen successfully onward. He passed his apprenticeship in a mercantile establishment, and soon after this was finished, he commenced business on his own account, as an agent for the sale of prizes, in which he continued till the close of the revolutionary war, and realized a considerable fortune, besides that which he obtained by his marriage with Miss Nichol, a young lady of great beauty. But the success of the Americans in their war of independence was fatal to the party to which he belonged, being that of the royalists; and he experienced, with his brethren in political opinion, the vae victis of an unsuccessful cause, in the loss of a considerable part of his property. Still, however, on his return to Scotland he had enough to purchase the estate of Sauchrie in Ayrshire. Here he resided for thirteen years, and held the offices of magistrate and deputy-lieutenant, of the county. From Sauchrie he removed to Falmouth in 1798, in consequence of being appointed agent for victualling the navy in the western ports of Great Britain. He afterwards changed his place of residence to Bristol, where he resided many years; and subsequently to Hoddesdon in Hertfordshire.
During these changes of scene and occupation, Mr. Macadam never appears to have lost sight of his early predilections in road-making. It formed the principal subject of his study while acting as one of the trustees upon certain roads in Ayrshire, and afterwards, when he had removed to England. It was certainly a bold experiment he proposed in a mode of constructing roads, by which the practice that had prevailed for thousands of years was to be abandoned in favour of a new theory. But it was the proposal of an eminently practical, sagacious, and scientific mind, that had revolved the subject in all its bearings during the period of an ordinary lifetime, and whose days were still to be continued, to carry it into execution. A full opportunity for the commencement of his plan occurred in 1815, when he was appointed surveyor-general of the Bristol roads; and after the first trials were made, the result was so satisfactory, that the new mode of road-making came into general adoption over the whole kingdom. After the excellence of his method had been sufficiently tested for highways, the fitness of its adoption for streets came next in question; and upon this subject Mr. Macadam was examined by a committee of the House of Commons in 1823. He then so clearly demonstrated the propriety and advantage of converting the ruble granite causeway of the principal streets of cities into a smooth pavement, like the country roads he had already constructed, that the change was adopted in London, Edinburgh, Dublin, and our principal towns.
An immense quantity of public labour was thus brought under the superintendence of Mr. Macadam, by which he might have accumulated profits to an indefinite amount, while his character as a public benefactor would have remained untouched. But superior to every selfish consideration, he confined his services to superintendence, and nothing more for he thought that an engineer should never act as a contractor, because where the offices are combined,
