How to Measure the Shock of an Earthquake
Dr. Buckland relates that in certain places liable to earthquakes, their extent has been measured by bowls of treacle, the inclination of the treacle in the bowl showing the quantum of shock; and elsewhere (by a watchmaker) in Scotland, by placing a clock against each of the four walls of an apartment, and marking the centre of the disk of the pendulum with chalk: when the shock took place, the derangement caused the pendulum to strike against the back and front of the clock-case, when, of course, a mark would be left indicative of the phenomenon, though not of its amount.