), a tower.
I. Stationary Towers.
The origin of the tower in fortification was doubtless, as Guhl and Koner
and others have remarked, a projection of the wall on either side of the
gate, to enable the garrison better to defend the entrance [see under
p. 467 b
]. From this swelling, so to speak, of the town
wall was developed (e. g. at Phigalia) the round or squareshaped or
hexagonal tower, originally merely a half-moon or three sides of a
square, but afterwards enclosed on all sides. The advantage of such an
addition at angles of the wall was obvious, and it became also customary
to have many such towers rising at intervals, so as to form
rallying-points and shelters for the defenders, if an escalade was
attempted. Such were the towers on the walls of circumvallation at
Plataea [cf. MURUS
As a further development, they were erected within cities, partly to form
a last retreat in case the city should be taken, and partly to overawe
the inhabitants. In almost all Greek cities, which were usually built
upon a hill, rock, or some natural elevation, there was a kind. of
tower, a castle, or a citadel, built upon the highest part of the rock
or hill, to which the. name of Acropolis
was given, as at
Corinth, Argos, Messene, and many other places. The Capitolium at Rome
answered the same purpose as the Acropolis in the Greek cities; and of
the, same kind were the tower of Agathocles at Utica (Appian, App. Pun. 14
) and that of Antonia at
Jerusalem (Joseph. Bell. Jud.
Lastly, we find towers standing alone as strongholds, such as the tower
at Andros instanced by Guhl and Koner (p. 68). We have further examples
of this in the tower of Hannibal, on his estate between Acholla and
Thapsus (Liv. 33.48
); the turris regia
of Jugurtha (Sallust, Sal. Jug. 103
); the tower of a private
citizen without the walls of Carthage, by the help of which Scipio took
the city (Appian, App. Pun. 117
in Spain, the tower in which Cn. Scipio was burnt (Appian, App. Hisp. 16
). Such towers were
common in the frontier provinces of the Roman empire (Ammian. Marcell.
28.2). See also Guhl and Koner, pp. 65 ff.; Droysen,
p. 254 f.
II. Movable Towers.
These were among the [p. 2.908]
most important engines
used in storming a fortified place. They were of two kinds. Some were
made so that they could be taken to pieces and carried to the scene of
operations: these were called folding towers (πύργοι πτυκτοὶ
or portable towers,
). The other sort
were constructed on wheels, so as to be driven up to the walls; and
hence they were called turres ambulatoriae,
(Veget. 4.17; Liv. 21.11
; Onosand. Strat.
42). But the turres plicatiles
generally made with wheels, so that they were also ambulatoriae.
The first invention or improvement of such towers is ascribed by
Athenaeus the mechanician (quoted by Lipsius, Oper.
iii. p. 297) to the Greeks of Sicily in the time of Dionysius I. (B.C.
405). Diodorus (14.51
) mentions towers on
wheels as used by Dionysius at the siege of Motya. He had before (13.54)
mentioned towers as used at the siege of Selinus (B.C. 409), but he does
not say that they were on wheels. According to others, they were
invented by the engineers in the service of Philip and Alexander, the
most famous of whom were Polyidus, a Thessalian, who assisted Philip at
the siege of Byzantium, and his pupils Chaereas and Diades (Vitr. 10.19
, s. 13). Heron (100.13) ascribes
their invention to Diades and Chaereas, Vitruvius (l.c.
) to Diades alone, and Athenaeus (l.c.
) says that they were improved in the time of Philip at the
siege of Byzantium. Vitruvius states that the towers of Diades were
carried about by the army in separate pieces. Respecting the towers used
by Demetrius Poliorcetes at the siege of Rhodes, see HELEPOLIS
Appian mentions the turres plicatiles
5.36, 37), and states that at the siege of
Rhodes Cassius took such towers with him in his ships, and had them set
up on the spot (ib. 5.72).
Besides the frequent allusions in ancient writers to the movable towers
), we have particular descriptions
of them by Vitruvius (10.19
, s. 13) and
They were generally made of beams and planks, and covered, at least on
the three sides which were exposed to the besieged, with iron, not only
for protection, but also, according to Josephus, to increase their
weight and thus make them steadier. They were also covered with raw
hides and quilts, moistened, and sometimes with alum, to protect them
from fire. The use of alum for this purpose appears to have originated
with Sulla at the siege of Athens (Amm. Marc. and Claud. Quadrig. ap.
Lips. p. 300). Their height was such as to overtop the walls, towers,
and all other fortifications of the besieged place (Liv. 21.11
). Vitruvius (l.c.
following Diades, mentions two sizes of towers. The smallest ought not,
he says, to be less than 60 cubits high, 17 wide, and one-fifth smaller
at the top; and the greater 120 cubits high and 23 1/2 wide. Heron
(100.13), who also follows Diades, agrees with Vitruvius so far, but
adds an intermediate size, half-way between the two, 90 cubits high.
Vegetius mentions towers of 30, 40, and 50 feet square. They were
divided into stories (tabulata
), and hence they are called turres contabulatae
). Towers of the three sizes just mentioned consisted
respectively of 10, 15, and 20 stories. The stories decreased in height
from the bottom to the top. Diades and Chaereas, according to Heron,
made the lowest story 7 cubits and 12 digits, those about the middle 5
cubits, and the upper 4 cubits and one-third of a cubit.
The sides of the towers were pierced with windows, of which there were
several to each story.
These rules were not strictly adhered to in practice. Towers were made of
6 stories, and even fewer (Diod. 14.51
Those of 10 stories were very common (Hirt. Bell. Gall.
8.41; Sil. Ital. 14.300
), but towers
of 20 stories are hardly, if ever, mentioned. Plutarch (Plut. Luc. 10
) speaks of one of 100 cubits
high used by Mithridates at the siege of Cyzicus.
The use of the stories was to receive the engines of war [TORMENTA], and slingers and archers were
stationed in them and on the tops of the towers (Liv. 21.11
). In the lowest story was a battering-ram [ARIES
]; and in the middle one
or more bridges (pontes
) made of beams and
planks, and protected at the sides by hurdles; or drawbridges [SAMBUCAE]. Scalingladders (scalae
) were also carried in the towers, and, when the
missiles had cleared the walls, these bridges and ladders enabled the
besiegers to rush upon them.
The towers were placed upon wheels (generally 6 or 8), that they might be
brought up to the walls. These wheels were placed for security inside of
The tower was built so far from the besieged place as to be out of the
enemy's reach, and then pushed up to the walls by men stationed inside
of and behind it (Caesar, Caes. Gal.
; Q. Curt. 8.10
). The attempt to draw them forward
by beasts of burthen was sometimes made, but was easily defeated by
shooting the beasts (Procop. Bell. Goth.
1.21). They were
generally dragged up the AGGER (Hirtius, l.c.
and it not unfrequently happened that a tower stuck fast or fell over on
account of the softness of the agger (Liv.
; Q. Curt. 4.6.9
). They were
placed on the agger before it was completed, to protect the soldiers in
working at it (Sall. Jugurth.
73; Caesar, Caes. Gal. 7.22
). When the tower was
brought up to the walls without an agger, the ground was levelled before
it by means of the MUSCULUS
These towers were accounted most formidable engines of attack. They were
opposed in the following ways.
- 1. They were set on fire, either by sallies of the besieged,
or by missiles carrying burning matter, or by letting men down
from the walls by ropes, close to the towers, while the
besiegers slept (Veget. 4.18; Sil.
- 2. By undermining the ground over which the tower had to pass,
so as to overset it (Veget. 4.20).
- 3. By pushing it off by main force by ironshod beams, asseres or trabes (Veget. l.c.).
- 4. By breaking or overturning it with stones thrown from
catapults, when it was at a distance, or, when it came close to
the wall, by striking it with an iron-shod beam hung from a mast
on the wall, and thus resembling an Aries. [p. 2.909]
- 5. By increasing the height of the wall; first with masonry,
and afterwards with beams and planks, and also by the erection
of temporary wooden towers on the walls (Caesar, Caes. Gal. 7.22; Veget. 4.19).
This mode of defence was answered by the besiegers in two ways.
Either the agger on which the tower stood was raised, as by
Caesar at the siege of Avaricum (B. G. l.c.), or
a smaller tower was constructed within the upper part of the
tower, and when completed was raised by screws and ropes (Veget.
l.c.). On these towers in general
see Lipsius, Poliorcet. in Oper.
vol. iii. pp. 296-356.
2.8-9) describes a peculiar sort of tower,
which was invented at the siege of Massilia, and called turris latericia,
It partook somewhat of the character both of
a fixed and of a besieging tower. It was built of masonry near the walls
of the town to afford the besiegers a retreat from the sudden sallies of
the enemy; the builders were protected by a movable cover; and the tower
was pierced with windows for shooting out missiles.
IV. Towers on ships.
Towers in every respect similar to the turres
(excepting, of course, the wheels) were
constructed on ships, for the attack of fortified places by sea (Caes. Civ. 3.40
; Liv. 24.34
; Appian, App. Mith.
, Bell. Civ.
5.106; Ammian. 21.12
V. Towers on elephants.
Small towers carrying a few armed men were placed on the backs of
elephants used in battle (Liv. 37.40
2.532 f.; Droysen, Gr.