MILITARY BRIDGES.

SECTION I.

On the Principles and Effects of the Motion ofWater in Rivers.

Although it is not the object of this work, toconsider the doctrine of the motion of water incanals and rivers, in relation to the purposes ofcivil life; yet so many deductions, highly im-portant to our present subject, may be madefrom it, that a few observations upon hydraulicswill be found a useful introduction to the variousmethods of passing rivers in military operations.

A knowledge of the principles of the motionand action of water, enables us to trace thatmode of unceasing operation, which occasionssinuosities—regulates the velocity of the cur-rent—forms eddies, and consequently banks—determines the natures of the sections at diffe-