Page:Popular Science Monthly Volume 69.djvu/232

228 easily be made too hastily. There is much contention over the merits of the different types of seismometrograph, which differ as widely as possible. It is perhaps not strange, in view of the new vistas opened for discovery, that the analysis of the records from some instruments not provided with compensating devices has brought out waves supposed to originate in the earth, which exist only in the vibration periods of the instruments themselves.

America's broad extent and her outlying territories and protectorates (Alaska, Cuba, Porto Rico, Panama, the Philippines, Hawaii, Guam and Tutuila), offer her special advantages for a correlated system of earthquake stations; but she will do well to wait until her principal station has been well established, her type of seismograph determined, and a corps of trained expert observers found. This will require some time, and can be greatly hastened if pride be put aside and some one of the thoroughly trained men available in Europe be invited to superintend the erection of the first earthquake station.

Some sacrifice the pioneer must always make, and so it happens that the English stations are fitted out with a type of instruments already obsolescent. On the point of establishing her outlying stations (German East Africa, Shan Tung, Samoa), Germany will be more fortunate. The maker of scientific instruments for almost the entire world, she has steadily perfected her types before launching upon the larger undertaking. America will have at least the consolation of profiting by the experience of the other nations during the past ten years, and there is need for much study of it.

The recent investigation of earthquakes has thus developed along two somewhat different lines: (1) the macroscopic study upon the ground of felt quakes, undertaken by men trained as geologists; and (2) the microscopic investigation of the distant, large, locally 'unfelt' quakes, undertaken at special earthquake stations by men trained as physicists. There is much need that these different lines of endeavor should be brought into as close a union as possible, for only through mutual support can the best results be achieved. As Dr. Sieberg, the secretary of the Strasburg station, told the writer, the more difficult of the seismograms afford equivocal data if not checked by the reports 'from the field.'

The American Association for the Advancement of Science brings the geologist into association with his brother the physicist, as well as with many other scientists who take an interest in investigations of such general interest as those upon earthquakes. The writer takes this opportunity to urge that the association follow the glorious example of its British cousin and select from its membership a committee to watch over the interests of seismological research in America and to direct the course of legislation in accordance with its teachings.