Probably most ti my young readers understand
the nature of a lock. As all water seeks a level,
there would be danger in an uneven country that
some parts of the canal would be left entirely



83 BOYHOOD AND MANHOOD OF

dry, and in otliers the water would overflow.
For this reason at intervals locks are constructed,
composed of brief sections of the canal barri-
caded at each end by gates. When a boat is go-
ing down, the near gates are thrown open and the
boat enters the lock, the water rushing in till a
level is secured ; then the upper gates are closed,
fastening the boat in the lock. Next the lower
gates are opened, the water in the lock seeks the
lower level of the other section of the canal, and
the boat moves out of the lock, the water subsid-
ing gradually beneath it. Next, the lower gates
are closed, and the boat proceeds on, its way. It
will easily be understood, when the case is re-
versed, and the boat is going up, how after being
admitted into the lock it will be lifted up to the
higher level when the upper gates are thrown
open.
If any of my young readers find it difficult tc
understand my explanation, I advise them to read
Jacob Abbot's excellent book, "Eo^lo on the
Erie Canal," where the whole matter is lucidly
explained.
Railroads were not at that time as common as
now, and the canal was of much more imponDauce



JAMES A. GASFIELD. 89

and valae as a means of conveying freight.
