TACTICS OF THE CAVALRY.
§ 85. The small tactical unit of the Roman cavalry, or of that formed on the Roman plan, was the turma, of 32 horses in rank and file. This was probably arranged in 4 ranks of 8 horses. Allowing 5 ft. front room to each horse, the turma would have a front of 40 ft., equal to that of the maniple. Taking 10 ft. depth for each rank, the depth of the turma would also be 40 ft., again equal to that of the maniple. The order of march could easily be formed from this order of battle.
§ 86. A regiment (ala) of 400 horses consisted of 12 turmae. The battle array of the cavalry would very likely resemble that of the infantry. It would then consist of several lines, two or three, with intervals between the turmae. A regiment of 12 turmae in 2 lines would have 6 in each line ; and the front, including intervals, would be 440 ft. Of course, if it should be desired to overwhelm the enemy with the momentum of the mass of horse, the intervals would be closed up.
§ 87. If the number of cavalry should be considerable, a larger tactical unit would be desirable. Three turmae, arrayed side by side, would amount to about 100 horses, with a front of 120 ft., equal to that of a cohort. A regiment (ala) of 400 horses would contain 4 such divisions.
§ 88. In attacks in mass, doubtless columns were formed of entire alae, perhaps 3 turmae front and 4 turmae (i.e., I6 ranks) deep. After the success was won, the turmae in the rear could be brought up in the front (turmatim) to pursue the scattered foe.