are generally on very lofty
summits, and they usually occupy the most commanding positions, so that
the view from them up and down the river is almost always very grand.
The castles were built by the dukes, and barons, and other feudal
chieftains of the middle ages, and they are placed in these commanding
positions in order that the chieftains who lived in them might watch the
river, and the roads leading along the banks of it, and come down with a
troop of their followers to exact what they called tribute, but what
those who had to pay it called plunder, from the merchants or travellers
whom they saw from the windows of their watchtowers, passing up and
down.

In fact these men were really robbers; being just like any other
robbers, excepting that they restricted themselves to some rule and
system in their plunderings, such as an enlightened regard for their own
interest required. If, when they found a vessel laden with merchandise,
or a company of travellers coming down the river, they had robbed them
of every thing they possessed, the river and the roads would soon have
been entirely abandoned, and their occupation would have been gone. In
order to avoid this result, they were accustomed to content themselves
with a certain portion of the value which the traveller was carrying;
and they called the money which they exacted a tribute, or tax, paid for
the privilege of passing through their dominions. They kept continual
watch in their lofty castles, both up and down the river, to see who
came by, and then, descending with a sufficient force to render
resistance useless, they would take what they pretended to consider
their due, and retreat with it to their almost inaccessible fastnesses,
where they were safe from all pursuers.

They often had wars with one another; and in the progress of these wars
the weaker chieftains became, in the course of time, subjected to the
stronger, and thus two or more small dominions would often become united
into one. These amalgamations went on continually; and as they advanced,
the condition of the cultivator of the ground, and of the peaceful
merchant or traveller, was improved, for the rules and regulations for
the collection of the tribute became more fixed and settled, and men
knew more and more what they could calculate upon, and could regulate
their business accordingly. Arrangements were made, too, to collect a
regular tax from the cultivators of the ground; and just so far as t