II. On the unit of length of a standard scale by Sir George Shuckburgh, appertaining to the Royal Society

In the determinations of the length of the seconds pendulum, which were made in London by Kater and at Greenwich by Sabine, and are described in the ‘Philosophical Transactions’ for 1818, 1829, and 1831, the distance between the upper and lower edges of the pendulum was measured off on a standard scale which had been constructed by Sir George Shuckburgh. The scale had not been compared with any of the modern standard scales, but it had been preserved with much care with the instruments appertaining to the Royal Society. In the autumn of 1888, M. le Commandant Defforges, an officer of the French Geodetic Survey, came to England to take a share in operations for the determination of the difference in longitude between Greenwich and Paris, and also to determine the length of a French seconds pendulum at Greenwich.