MUSEUM OF COMPARATIVE ZOOLOGY. 25 



But one recognized local shock was recorded during the year, 

 that of Feb. 6th, 1911, at 6h. 36m. 17s. a. m., Eastern standard 

 time. This shock was felt by the observer. None of the local 

 shocks reported by the daily press at points along the coast of 

 Maine or in the Merrimac valley were registered. 



From the beginning of the year 1911, the records of the Station 

 have been issued to several exchanges in the form of a mimeo- 

 graphed monthly bulletin. The following stations and observa- 

 tories now regularly send reports to the Geological Museum : — 



The International Seismological Bureau, Strassburg, Germany. 

 The Astronomical Observatory, Ottawa, Canada. St. Ignatius 

 College Observatory, Cleveland, O., J. S. S. Canisius College, 

 Buffalo, N. Y., J. S. S. Spring Hill College, Mobile, Ala., J. S. S. 

 Santa Clara College Observatory, Santa Clara, Calif., J. S. S. 

 St. Louis University Observatory, St. Louis, Mo., J. S. S. 

 Loyola College Observatory, New Orleans, La., J. S. S. N. Y. 

 State Museum, Albany, N. Y. University of Washington, 

 Seattle, Washington. 



The Strassburg International Bureau also transmits its " Monat- 

 liche Uebersicht iiber die Seismische Tatigkeit der Erdrinde." 



The Station clock has throughout the year been compared 

 almost daily with the chronograph of the Harvard Astronomical 

 Observatory by means of the telephone. Mr. G. M. Flint has 

 performed the routine work of the instrument room except during 

 a few days in April, and from Aug. 1st to Aug. 25th, 1911. In 

 August the routine duties including the care of the Station clock 

 were discharged by Mr. Sidney Holmes, janitor. 



The pendulums have been allowed to swing without damping 

 as heretofore owing to the difficulty in securing a sufficiently 

 delicate adjustment of the air damping devices. This is a serious 

 defect in arriving at an accurate measurement of the motion of 

 the ground during the passage of seismic waves. A comparison 

 of the times of beginning of the first preliminary waves at this 

 Station with similar data obtained by frictionless photographic 

 registration at Ottawa makes it clear that the mechanical registra- 

 tion here employed retards the initial swinging of the pendulums. 

 It is also probable that the initial seismic energy is somewhat 

 dissipated in its passage through the deep superficial deposits 

 upon which the pier rests. Belated readings amounting to as much 

 as 30 sees, in the case of certain records seem to be attributable 

 to one or both of these now unavoidable causes. I wish also to 

 call attention to the recommendation of the International Seismo- 



