Oct. 6th, 21 h. 9 m.—A smart shock of earthquake at San Francisco.
Oct. 14th, 1 h. 8 m.—Two heavy shocks of earthquake were felt at Mission San Juan, and another severe shock at 10 h. 25 m., the movement was from west to east.
Dec. 11th, 20 h. 52 m.—A shock of earthquake at San Francisco. This shock was felt at San José at 20 h. 51 m., and was evidently more severe there than at San Francisco.
During 1864, we have had twenty-one days on which earthquakes have occurred, and of at number there have been two days, (March 10th and July 21st) in which more than one shock has taken place within the twenty-four hours of each day.
The British Colonist, of Victoria, Vancouver Island, furnishes the following statement:
From a gentleman who has resided on Vancouver Island for 15 years, we learn that slight earthquakes have occurred annually, with one or two exceptions, during the entire period. Only on one occasion (1858) does he remember experiencing a shock at all approaching in severity that of Saturday morning, October 29th 1864. The oscillation, as on this last occasion, has almost invariably been from west to east: and he accounts for this, by supposing that the internal convulsion of the earth beneath, has to find vent in the crater of Mount Baker, situated to the east of us. This volcano has not had any visible eruption for several years. On the last occasion, it sent up a dense volume of smoke, and occasionally a bright flame was seen to issue from the fiery furnace. Another old resident informs us, that the appearance of the summit of Mount Baker has undergone a material change within late years, giving room for the conjecture that large portions have crumbled away and descended into the yawning abyss of the crater which lies between the two highest peaks.
Relating to earthquakes at San Francisco and its immediate vicinity, we have an item of interesting information relating to their effects at the Farrallones Islands, situated some fifteen miles to the west of the city. It appears, upon the testimony of the lighthouse-keeper at these Islands, and who has resided there for several years, (seven or eight), that but two of the whole number occurring at this city, have been felt at the Islands, and of these he made an official record. The first was the shock of Dec. 23d, 1862, and that of June 22d, 1864.
From 1857 to date, we have seven years, during which time twenty-five shocks have been authenticated at San Francisco, while two only of the number have been felt at the above locality west of the city.