4.7-inch guns, with 8-inch mortars and quick firers. They were
in the relative number of two, four, two and four for the major
forts, and two, two, one and three for the minor _fortins_, as
such were termed. The grand total was estimated at 400 pieces.
In their confined underground quarters the garrisons, even of the
major forts, did not exceed eighty men from the engineer, artillery
and infantry branches of the service. Between Fort Pontisse and
the Dutch frontier was less than six miles.

It was through this otherwise undefended gap that Von Kluck purposed
to advance his German army after the presumed immediate fall of
Liege, to that end having seized the Meuse crossing at Visé. The
railway line to Aix-la-Chapelle was dominated by Fort Fleron, while
the minor Forts Chaudfontaine and Embourg, to the south, commanded
the trunk line by way of Liege into Belgium. On the plateau, above
Liege, Fort Loncin held the railway junction of Ans and the lines
running from Liege north and west. Finally, the forts were not
constructed on a geometric circle, but in such manner that the
fire of any two was calculated to hold an enemy at bay should a
third between them fall. This was probably an accurate theory before
German guns of an unimagined caliber and range were brought into
action.

In command of the Belgian forts at Liege was General Leman. He had
served under Brialmont, and was pronounced a serious and efficient
officer. He was a zealous military student, physically extremely
active, and constantly on the watch for any relaxation of discipline.
These qualities enabled him to grasp at the outset the weakness
of his position.