Shortly after the meeting of the British Association last year (1881),a the instrument with which my brother and I were experimenting at the Cavendish Laboratory, at Cambridge, broke down, through the snapping of the wire which supported the pendulum. A succession of unforeseen circumstances have prevented us, up to the present time, from resuming our experiments.

The body of the present Report, therefore, will merely contain an account of such observations by other observers as have come to our knowledge within the past year, and it must be taken as supplementary to the second part of the Report for 1881. The Appendix, however, contains certain theoretical investigations, which appear to me to throw doubt on the utility of very minute gravitational observations.

The readers of the Report for 1881 will remember that, in the course of our experiments, we were led away from the primary object of the Committee, namely, the measurement of the Lunar Disturbance of Gravity, and found ourselves compelled to investigate the slower oscillations of the soil.

It would be beyond the scope of the present Report to enter on the literature of seismology. But, the slower changes in the vertical having been found to be intimately connected with earthquakes, it would not have been possible, even if desirable, to eliminate all reference to seismology from the present Report.