National Geographic : 1900 Nov
THE MANILA OBSER VA TORY With these micrometers one ten-thousandth of the millimeter can be read.* Since the year 1888 the astronomical section has had a twofold duty: first, it has given every day the exact hour of noon in Manila civil time, and, second, it has regulated nearly all the chronometers of steamers and sailing vessels entering Manila Bay. So acceptable has been this work of the observatory that more than a hundred chronometers have been brought in each year since January 1, 1894. The astronomical department has also constantly informed the pub lic of Manila of all phenomena worthy of notice, such as solar and lunar eclipses visible in the locality, the appearance of comets, transits of Mercury, and meteoric showers. The building and entire equipment were provided at the exclusive expense of the Jesuit fathers. The astronomical department was to have been officially recognized by the Spanish government for the financial year 1898, but unfortunately war embarrassed all the scientific projects so much cherished by the fathers of the observatory. The study of earthquakes and seismic phenomena dates almost from the beginning of the observatory, when the first instruments used for this study were pendulums of very simple construction, for tracing the horizontal and vertical movements of the ground. Other instruments were afterward acquired for direct observation and for recording purposes. Soon after the great earthquake of 1880, which nearly laid the city of Manila in ruins, the Rev. Father Faura, director of the observatory, published a very interesting work about the earthquakes. Hourly microscopic observations were commenced in January of 1881, and in 1887 the Monthly Review began to be illus trated with the records of earthquakes that occur so frequently in some part or other of the archipelago. The seismic instruments now actually employed are all firmly fixed to the base of a massive pier that runs through the right tower of the main building. A fair idea of these instruments may be had in the work La Seis mologia en Filipinas(pages 4-16). This publication of the observa tory is a very important one, and contains a detailed catalogue of the long series of earthquakes that have been felt in the Philippines from 1599 to 1890, with the dates of their occurrence and a statement of their severity. Father Joseph Coronas has recently published an ac * See the pamphlet: Der Photo chronograph in seiner Anwendung zu Polh6henbestimmun gen, Von Dr Otto Knopf in Jena (Sonderabdruck aus der Zeitschrift fur Instrumenten-kunde 1894, Heft 3), (Verlag von Julius Springer in Berlin).