GREGORY, David, the son of the reverend John Gregory, minister of Drumoak, in the county of Aberdeen. He was born about the year 1628, educated by his father for business, and bound as an apprentice to a mercantile house in Holland. But as his love of letters exceeded his desire of money, he relinquished commerce in the year 1655, and upon the death of an elder brother he succeeded to the estate of Kinnardie, about forty miles from Aberdeen, where he resided many years, and had no fewer than thirty-two children born to him by two wives. Three of his sons became eminent for their extensive literature, and were at one time professors of mathematics in the universities of Oxford, Edinburgh, and St Andrews.
In the country where he dwelt he was the first person who had a barometer, to the oscillations of which, according to the changes of the weather, he paid great attention, and was once in danger of being tried by the presbytery for witchcraft or conjuration. He was waited upon by a deputation of ministers, who inquired into the truth of certain reports which had come to their ears; but he so far satisfied them as to induce them to waive a prosecution against a man who, by the extensive knowledge he possessed of medicine, was a public blessing to the country.
About the beginning of the eighteenth century he removed to Aberdeen, and during the wars of Queen Anne's reign, turned his attention to the improvement of artillery, and executed a model of an engine intended to render cannon more destructive. Dr Reid knew a clock-maker who had been employed to make the model of this engine; but as he made many different pieces without knowing their design, or the method of uniting them, he could give no consistent account of the engine. Satisfied with his invention by various experiments, Mr Gregory desired his son to show it to Sir Isaac Newton, but to conceal the name of the inventor; Sir Isaac however was much displeased with it, and declared that the inventor was more entitled to punishment than reward, as it was solely calculated for destruction, and might come to be known to the enemy. That great man urged the necessity of destroying it; and it is probable that Mr Gregory's son, the Savilian professor, followed his advice, for the model was never found.
When the rebellion broke out in 1715, the old gentleman went a second time to Holland; but when the insurrection had been put down, he returned to Aberdeen, where he died about 1720, in the ninety-third year of his age, leaving behind him a history of his own times, which was never published.