H. O. WOOD [see 1 of “References” at end of paper] gives 1844 as the date of the inauguration of the Manila Observatory. This may be merely a misprint, but it is 21 years too early. Elsewhere [2]he gives 1884. (Doubtless this date relates to subsidizing by the Spanish Government as stated later in this paper.—Editor) The Manila Observatory originated with a series of meteorological observations which were commenced on January 1, 1865.In the Observatory Reports of 1868 there is mention of the record of an earthquake by the horizontal seismoscope, and hence the installation of this pendulum was made in the period 1865–1868; the exact date was not recorded. I say “there is mention in the report of 1868;” it would probably be more accurate to say that “there was mention,” for I doubt if any of those reports are still in existence in any part of the world; they no longer exist in Manila. This seismoscope was a simple pendulum having a 15‐inch suspension, carrying a point in the lower surface of the bob, and the point traced its motion in lycopodium powder sprinkled on a glass plate of spherical shape. There was also a vertical seismoscope consisting of a long spiral spring terminating in a bob which pushed an indicator down a scale to show the amount of vertical motion. In the Observatory we had a trace of the mark made by the horizontal seismoscope in an earthquake of 1872, the oldest record in the Observatory. However, this was not the first pendulum in the Philippines. A very complete report was issued by the Spanish Government on an earthquake of 1851, and mention is made therein of a pendulum in operation in a town in southern Luzon, and the amplitudes of its oscill