He even modified his way of writing English in accordance with German custom, as is shown by the plentiful scattering of capitals through his sentences, and by a certain ponderosity of style which savours of German originals. The dissensions as to the mode of election to the Mineralogical chair caused it to remain vacant for three years; so that Whewell, about the choice of whom there never seems to have been any doubt, had no immediate opportunity of turning to account his newly-acquired knowledge. He therefore, with even more than characteristic energy, turned his attention to two most opposite subjects, Theology, and the Density of the Earth. In the summer of 1826 he commenced a series of investigations on the latter subject at Dolcoath Mine, Cornwall, in conjunction with Mr Airy. The essential part of the process was to compare the time of vibration of a pendulum at the surface of the earth with the time of vibration of the same pendulum at a considerable depth below the surface. Unfortunately the experiments, which were renewed in 1828, failed to lead to any satisfactory result, partly through an error in the construction of the pendulum, partly through a singular fatality, by which, on both occasions, they were frustrated by a serious accident. The account he gives of himself, and of the way in which the researches were regarded by the Cornishmen, is too amusing not to be quoted. It is contained in a letter to his friend Lady Malcolm, and is dated ‘Underground Chamber, Dolcoath Mine, Camborne, Cornwall, June 10, 1826: