The evidence they afforded of his capacity, and the fact that he already had received a scientific appointment, probably led to his being selected in the same year to make some geological and mineralogical investigations in Scotland. He was in 1809 to identify limestone suitable for use in gunpowder making. He was also consulted on the suitability of the chief Scottish mountains for a repetition of the pendulum experiments previously conducted by Nevil Maskelyne and John Playfair at Schiehallion, and on the deviations of the plumb-line along the meridian of the Trigonometrical Survey. In the course of the explorations necessary for the purposes of these reports he made extensive observations on the geology and mineralogy of Scotland. He formed also a collection of the mineral productions and rocks of that country, which he presented to the Geological Society in 1814. In that year he was appointed geologist to the Trigonometrical Survey; and in 1816-1818 he was president of the Geological Society.