Aciem instruere, to form line of battle.
Aciem dirigere, to align the front.
Cohortes disponere, to deploy the cohorts.
Consistere, to halt.
Legiones explicare, to deploy the legions.
Torquere agmen ad dextram (sinistram),
to change the direction of the march (right or
ORDER OF BATTLE.
§ 56. The tactical unit of the legionof Cæsar was the cohort (§ 6). The men of any one cohort as a rule remained together, and all movements of the legion were made by cohorts.
We may estimate the front of a cohort in line of battle at I20 ft.
§ 57. In all estimates of extent of the legion in battle, march, or camp, we follow Rüstow's figures, which are based on the average field strength of the legion, 3600 men, not on its nominal, or full, strength.
In relating a fight at Ilerda, in Spain, Cæsar states that his troops were drawn up across the top of a ridge, along which the enemy were advancing. He then says that this ridge was just wide enough for three cohorts in order of battle (tres instructae cohortes, C. I, 45). The ridge is readily recognized to-day, and measures just about 360 feet across. The circumstances of the fight were such as to leave no doubt that the cohorts were drawn up without any intervals between them; so that this measure gives us the actual front of the cohorts. Thus we get the estimate of 120 ft. for the front of one cohort.
The three maniples of a cohort might have been arrayed side by side, or one behind the other. Rüstow holds to the former arrangement, and Göler to the latter. The reasoning of Rüstow (R. p. 36