126 EAKTHQUAKES ON THE PACIFIC COAST 



1688. October 24; 2:60 a. m. 



East Oakland: (V) Mr. Blinn's Observatory. The duplex seis- 

 mometer plate shows a trace from S. to N. in general direction. 

 The first trace on the plate is that of a single wave about 2ni. in 

 amplitude (magnified four times) followed by small tremors.^ 

 Chabot Observatory: the plate of the duplex seismometer shows 

 the first wave strongly towards the N. E. The trace of this 

 wave (magnified four times) is a straight line 6 mm. long. This 

 is followed by two waves of the earth as it regained its original 

 position. The motion of the earth is contrary to that of the pen 

 on the plate. 



1888. October 25; in tbe nlsht. 



Mr. Blinn's Observatory. The duplex seismometer gives a tremor, 

 and the general direction of the trace on the plate is S. E. to 

 N. W. 



1888. No-F ember 4; 3:36 a. m. 



Lick Observatory (VI). — E. S. H. Mr. Barnard gives the time as 

 3h. 3714m., plus or minus i/^m. The duplex seismometer gives a 

 very complex knot of curves ending by a trace on the plate 

 towards the S. W. 



1888. No-Fember 18; 2:28 p. m. 



S. F., 917 Pine Street: two shocks north and south (VII) registered 

 on seismometer. Another light shock at .5.38 p. m. — J. R. J.^ — 

 S. F., 2h. 26m. p. m. Sharp vertical shock, duration 4 seconds.— 

 T. T.— San Rafael: 2.30 p. m., N. and S.— Oakland: 2.29 p. m.; one 

 chimney fell (VII?). — Berkeley: 2.28 p. m.; duration 7 sec; a 

 third shock at 5.35 p. m. (S. F. Examiner, Nov. 19.) 



Lick Observatory: not felt, not registered. — Chabot Observatory: 2h. 

 27m. 53s., very sharp shock; 3.30, slight; 5h. 37m. 20s., sharper 

 than the second shock. The duration was 3 sec. The trace on 

 the duplex seismometer is a very complicated circular knot of 5 

 to 6 mm. diameter (magnified four times) with a looped excur- 

 sion of the pen toward the east 6 mm. from the center of the 

 knot, and another straight one from the center to the W. S. W., 

 also of 6 mm. All three shocks are on this single plate. — In Oak- 

 land no real damage was done. Two or three chimneys were 

 overthrown and panes of glass were broken (VI, or VII?). — East 

 Oakland: 2.29 p. m., N. to S., duration 2 sec; 3.45 p. m., very 

 light; 5.36 p. m., E. to W., duration 2 sec— (S. F. Bulletin, Nov. 

 19). — Napa: 2.36 p. m., duration 10 sec. — S. F. Chronicle. Nov. 19. - 

 Hay wards, San Leandro, Niles; not felt. — Mr. Burckhalter. — Cleir 

 Lake: not felt.— Capt. R. S. Floyd. 



It is also reported by Capt. Edmundson of the ship *" Drumlanrig," 

 that he found soundings of 35 fathoms, 35 miles S. W. of the 

 Farallones where no shoal is now known to exist. It is supposed 



