His father then destined him for the naval service, which he entered on the appointment of the Mareschal de Castries, the Minister of Marine, and made several voyages to the West Indies. While in this position, although only fifteen years old, his mechanical talents showed themselves on many occasions, and he surprised his captain by the production of a sextant of his own manufacture, with which he took his observations. In 1792 Brunel returned to France, where he found the revolution at its height, and, like all who entertained Royalist principles, was compelled to seek safety by flight, which with difficulty he effected,[7] taking refuge in the United States of America. Here, driven by necessity to the exercise of his talents, he followed the bent of his inclination, and became a civil engineer and architect. His first engagement in this capacity was on the survey of a tract of land near Lake Erie; he then became engaged in cutting canals, and was employed to erect an arsenal and cannon foundry at New York, where he erected several new and ingenious machines. He was also engaged to design and superintend the building of the Bowery Theatre, New York, since destroyed by fire, the roof of which was peculiar and original in its construction. Brunel now rose high in the estimation of the citizens of New York; they appointed him their chief engineer, and in that capacity he organized an establishment for casting and boring ordnance, which at that time was considered unsurpassed for its novelty of design and general practicability. Previously to this the idea of substituting machinery for manual labour in making ships' blocks had long occupied Brunel's mind, and in 1799, having matured his plans, he determined upon coming to England, finding that the United States were unable to afford full occupation for his inventive genius. In the month of May of the same year Brunel took out his first patent in England, which was for a duplicate writing and drawing machine. His next invention was a machine for twisting cotton thread and forming it into balls; it measured the length of thread which it wound, and proportioned the size of the ball to its weight and firmness. This machine was not, however, patented, and it became rapidly and generally adopted without bringing any advantage to the inventor. Brunel's next contrivance was a machine for trimmings and borders for muslins, lawns, and cambrics, somewhat of the nature of a sewing machine. Shortly after this he patented his famous block-machinery, which he submitted for the inspection of the Admiralty in 1801.