86 The American Geologist. August, loo-. 
river inundations. He also observed numerous circular cav- 
ities called sink holes from ten to thirty yards wide and twenty 
feet or more deep. 
Humboldt in his Casmos (quoted in second vol. of Lyell's 
princi]:)les) says that the New ]\Iadrid earthquake presents 
one of a few examples on record of the incessant quaking of 
the ground for several successive months, far from any vol- 
cano. The direction of the fissures varied from lo" to 45" 
west and north and were often parallel. Lake Eulalie, near 
Xew Madrid, 300 by 400 yards, was suddenly drained. All 
the trees growing on its bottom were less than 34 years old 
and consisted of cottonwood, willow, horny locust, different 
from those growing on higher grounds, now elevated -by 12 
to 15 feet. On them are hickory, black oak, gum and white 
oak of more ancient age. 
An interesting account of the earthquake may be found in 
Casseday's History of Louisville, Ky., Ch. A'. 
On the i6th of Dec, 1811. at 2:15 A. M. a shock was felt at Louis- 
ville, Ky.. the details of which were noticed and written out by Jared 
Brooks and first published in 1819 in Dr. McMurtrie's "History of 
Louisville." Mir. Brooks said that it seemed as if the surface of the 
earth was afloat and set in motion by a slight application of immerse 
power, then .a boiling action succeeds, houses oscillate, gables and 
chimneys of many houses are thrown down. From the earliest tremor 
to the last oscillation was about four minutes. This was followed by 
two other shocks during the same day, and of almost equal power. 
During the prevalence of earthquakes it was customary to suspend 
«m object to act like a pendulum to determine the amount of danger, 
any time at Louisville. It occurred at 3:15 A. M. and was preceded 
Brooks refers to that of February 7, 1812. as the most violent felt at 
any time at Louisville. It occured at 3: 15 A. M. and was preceded 
by frequent slight motions for several minutes. The duration was about 
four minutes, then gradually moderated by lesser shocks for about two 
hours; these were followed by a succession of distinct tremors or jat- 
rings at short intervals until 10 A. M. when there occurred a severe 
shock, after which there were frequent jarrings and slight tremors 
during the day, at least one every ten minutes. At 8:10 P. M. there was 
a shock of second-rate violence and soon after two others connected by 
a continual tremor of considerable severity. The last shock was viol- 
ent in the first degree but of too short duration to do much injury 
;\.t 10:10 P. M. there were violent shocks of the second degree in- 
creasing to tremendous, and for seven seconds, then tremulous, then 
severe for five minutes followed by frequent tremors and a shock of 
third-rate violence. The action then ceased for a while. Mr. Brooks 
gives a table nf violence and time of shocks : 
