304 RECORD OF SCIENCE FOR 1886. 



In a letter to Nature, under date February 28, 1886, Professor Sekiya 

 gives a specimen of the earthquake records wiiicli are now issued from 

 the University of Tokio. Regular observations are there made by the 

 Meteorological Bureau by means of the horizontal pendulum and verti- 

 cal motion seismographs of Milne, Gray, and Ewiug, which produce 

 ■continuous diagrams on a revolving glass plate or drum. The Meteoro- 

 logical Bureau has also carried out a set of observations for the deter- 

 mination of the area shaken in each earthquake, by means of reports 

 gathered from over six hundred local offices throughout the Empire. 

 The results are confirmatory of those reached by Milne in previous 

 similar study. The total number of earthquakes in Japan in 1885 was 

 four hundred and eighty-two, equivalent to 1.3 shakings per day. Of 

 these two hundred and thirty-five were local, not affecting an area of 

 more than 100 square miles. The maximum area of any one earthquake 

 was 34,700 square miles. The intention to continue similar observa- 

 tions is announced. (Nature, xxxiii, G03.) 



The Cambridge Scientific Instrument Company is now prepared to 

 manufacture seismographic instruments after the designs of Prof. J. A. 

 Ewing, of Dundee, formerly of Japan. The instruments are described 

 by Ewing, with ilLustratious, in Nature, xxxiv, 343, and consist essen- 

 tially of a pair of bracket seismographs for horizontal motions and a 

 vertical motion instrument, all recording on a glass plate revolving 

 by clock-work. The cost of this apparatus complete is £57 5s. The 

 bracket seismographs with recording apparatus alone cost £40. The 

 duplex pendulum seismograph, recording on a fixed plate and com- 

 plete in itself, costs £14. These instruments are essentially similar to 

 those described by Ewiug in his memoir on Earthquake Measurement. 



James White, of Glasgow, also advertises the Milne and Gray seismo- 

 graph, improved from that figured in Milne's " Earthquakes/'page 39, 

 and made under Mr. Gray's personal supervision, for £55. It records 

 both horizontal and vertical motions on a revolving drum, by means of 

 two conical pendulum seismographs for the horizontal components and 

 a compensated spring seismograph for vertical motions. 



The U. S. Geological Survey has been experimenting on cheap forms 

 of seismoscopes, which could be provided in considerable numbers and 

 distributed to competent observers in the interest of its seismological 

 work. Final results are not yet public, but good progress has been 

 made toward an instrument which should meet the necessary conditions 

 of reliability and cheapness. 



Professor E wing's instruments are in use at, or have been ordered by, 

 the University, Tokio ; the Meteorological Observatory, Tokio ; the Geo- 

 graphical Bureau, Manila 5 the Ben Nevis Observatory ; and the Lick 

 Observatory, California. M. Cruls is also desirous of setting up seis- 

 mographic instruments in the new building about to be erected for the 

 Bio Observatory, Brazil. (Nature, xxxiv, 604.) 



