14 REPORT ON THE TIMBERS OF THE 
together; again, they grow only in streaks. After passing 
this flat woods, there are two principal causes of change in 
the timbers: one is change of height above drainage, which 
always produces corresponding changes in the species of tim- 
bers; the other is change in the position of the gravel beds. 
relative to the surface of the ground. Underlying the whole 
of the Purchase country is a bed of pebbles, whose thickness 
I could not accurately ascertain. This pebble bed is, in some 
parts of the country, as much as fifty feet below the surface 
of the ground; in others, for miles, it is on a level with the 
surface, whose whole formation consists of these pebbles. I 
did not have the time or the means to investigate the course 
of these pebble beds, but wherever they lie near to, or form 
the surface soil,the timbers are very poor, and consist mostly 
of black-jack and scrub oak. The fine timbers are always. 
found where these beds are at a considerable depth below the 
surface soil. 
I might call attention here, in passing, to two irregular 
marsh-ponds of the Purchase, one a few miles south of Pa- 
ducah, the other a few miles north of Mayfield. They are 
low, undrained marsh lands, the former irregularly round, the 
latter oblong, and both heavily timbered with swamp timbers. 
Buzzard pond, as the one near Paducah is called, contains a. 
great deal of bartram oak, over-cup, the people call mt 
Cypress pond, near Mayfield, takes its name from its prin- 
cipal timber. It is one of the cypress swamps often found in. 
the Southern States. 
SUCCESSION OF TIMBERS. 
Between Murray and Mayfield there is a considerable area. 
of more or less flat table land, through which no water passes, 
except the extreme head waters of West Fork of Clark river, 
and a few other little branches, most of which are dry nearly 
all the year. I was surprised, after leaving Benton and pass- 
ing into this table land, to find that the woods consisted only 
of saplings or tall, slim, young trees, from forty to seventy 
feet in height, but not more than twelve to twenty inches im 
150 
