A. T. Mahan,
Lessons of the war with Spain and other articles
“ Like the land, the sea, as a military field, has its important centres, and it is not controlled by spreading your force, whatever its composition, evenly over an entire field of operations, like butter over bread, but by occupying the centres with aggregated forces—fleets or armies—ready to act in masses, in various directions from the centres. This commonplace of warfare is its first principle. It is called concentration, because the forces are not spread out, but drawn together at the centres which for the moment are most important. ”
