No. 200.] 
3)29 
The trees growing in these swamps are commonly black ash, tamarack, 
and cedar. In the southern part of the county are several swamps of 
this character, where the vegetable matter covers a deposit of shell marl 
— both substances of great value as manures. 
Lake Shm^e, 
The lake shore of this county is for the most part low, the land gra- 
dually declining to the level of the water. The action of the waves, 
together with the ice, have mised beaches, which in many places protect 
the land from inundation during high winds. In the eastern part of 
the county, the banks are abrupt, consisting of gravel, sand and clay. 
These banks are gradually worn away by the waves, and the materials 
carried to points where the banks are low. By this wearing action the 
lake encroaches upon the land in some places, while the land is gaining 
upon the lake in others. In the course of a year, several feet of these 
banks are abraded by the waves. During some years, the lake is higher 
than in others, so that the wearing action is not uniform. The wind 
from the northeast carries the abraded materials towards the mouth of 
the Genesee, and thus aid in filling up the channel, and extending the 
shoals and sand-bars in the vicinity. The shores being low on the west 
of the Genesee, a west or northwest wind brings few materials from that 
quarter. When the lake is higher than usual, even the low beaches are 
worn down, and the materials transported to other parts of the shore. 
The bank of the lake, from the Genesee river to the eastern bounda- 
ry of the county, is from ten to thirty feet high. From the Genesee 
to the western line of the county, the shore is generally low, or raised into 
a beach a few feet above the lake. For the last two years the lake has 
been higher than for many years before; this is evidenced by the waves 
undermining the banks which had become overgrown with trees and 
shrubs. There is a tradition of a periodical rise of the lake, but it is not 
verified by observation. Although this rising of the lake is not periodi- 
cal, it does occur at intervals, and at such times the beaches and sand- 
bars are removed, to be deposited in other places, and to fill up the 
mouths of streams. It therefore becomes a matter of importance to pro- 
tect the shores from such effects, and from the loss of land thus sustained. 
To do this, trees and shrubs should be permitted to grow on the banks, 
and shrubs with strong roots might be planted to effect the same object. 
The Irondequoit bay is so situated, that it receives the abraded mate- 
rials of the banks of the lake, from both the east and west. This bay 
is about one mile and a quarter wide, gradually narrowing southward; 
[Assem. No. 200.] 38 
