H. W. Halleck,
Elements of Military Art and Science
“ But an acquaintance with infantry, cavalry, and artillery duties is not the only practical knowledge requisite in war. In the practical operations of an army in the field, rivers are to be crossed, bridges suddenly erected and suddenly destroyed, field-works constructed and defended, batteries captured and destroyed; fortifications are to be put in order and defended, or to be besieged and recaptured; trenches must be opened, mines sprung, batteries established, breaches made and stormed ”
