Several slights shocks have been felt in the course of last week - - Thursday night between the hours of eleven and one o'clock two shocks of considerable severity were felt here - - duration of the first a fourth of a minute, the last considerably less.
As all authentic information from near the western extremity of our civilized population, concerning the earthquakes, must be acceptable to the public (whose eyes are turned to that quarter for the cause,) we insert the following extract of a letter from Robert Morrison, Esq., a respectable inhabitant of Kaskaskia, to a gentleman in the town. N. B. Kaskaskia is a little more than 100 miles above the mouth of the Ohio River, and 60 miles below St. Louis.
'We have been very much alarmed by a repetition of earthquakes since the morning of the 16th of Dec. The first happened about half past 2 o'clock - - it was extremely severe, and was succeeded by another one at sunrise the same morning, but somewhat less terrible. The subsequent ones have been more gentle, and occurred three times in about every 24 hours for more than 10 days. For about 20 days last past, we have not experienced more than 3 or 4 shocks, and these but slightly felt. (This last letter was written in January.)
'Various conjectures have arisen in the minds of our readers philosophers as to the causes that may have produced them. Some suppose they are occasioned by a volcanic eruption, others seem to think they were produced by the comet's near approach to the earth. There are, however, a few who are of a differing opinion and ascribe it to electricity alone. The latter opinion I have adopted.'