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Bill Thayer

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The artillery and siege trains of the Trajan column
This webpage reproduces a section of
A Description of the Trajan Column
by John Hungerford Pollen

printed by George E. Eyre and William Spottiswoode,
printers to Queen Victoria
London, 1874

Text and engravings are in the public domain.

This page has been carefully proofread
and I believe it to be free of errors.
If you find a mistake though,
please let me know!

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Sacrifices and religious rites

 p52  I will conclude these notices with a few words on the fortifications, of which such numerous varieties occur in the sculptures on the spiral of the column. They are generally represented as made of hewn masonry, which could not have been the case with Roman fortified camps, at least during the progress of a march.

 p53  Systems of fortification employed by Trajan and the Dacians

Valla, ramparts, and ditches were commonly made of turf and timber by the Romans, and we shall best illustrate the bas-reliefs representing these fortifications by a reference to the more complete descriptions given of similar works by Julius Caesar. From the life by the Emperor Napoleon III I borrow the accompanying illustrations.


[image ALT: An engraving of a complex series of defensive fortifications, of wood, described in detail in the text of this page.]

Fig. 23.

In the Bell. Gall., Book IV is a detailed account of the Roman field works at Alessia. First, a fosse was dug 20 feet wide with vertical sides so as to be as wide at the bottom as on the ground level, in order to make this a real protection against night attacks along lines so extensive, and which men could ill be spared to guard along its whole length, and to protect workmen from the missiles of the enemy during the day. 400 feet behind this fosse was the wall or vallum. He then dug two fosses 15 feet wide, filling the inner fosse nearest the town with water from the river Oserain. Behind this inner fosse was raised a rampart and palisade, together 12 feet in height. Against this was placed a fence of hurdles with battlements, loricam pinnasque. Strong forked branches were laid horizontally at the point of junction of the hurdle fence with the rampart to make them more difficult to scale. Towers were raised with intervals of 80 feet between. Tops or large branches of trees, of which the extremities were sharpened to a point, were planted in a fosse five feet deep, and every three connected together at the bases so as to make it difficult to pull them  p54 up. The branches rose above the ground in the shape of a hedge. Five rows of these were planted contiguous to and interlaced with each other. They were called cippi. In front of these were scrobes, pitfalls three feet deep, disposed in the form of a quincunx. In the centre of each hole was planted a stake as thick as a man's thigh pointed and hardened in the fire. This stake rose about four feet above the ground. To make it firmer the earth in which it was planted was well rammed down, and the rest of the excavation covered with thorns and brushwood to conceal the trap. They were in eight rows three feet apart and were called lilia on account of the resemblance of their form to the bell of that flower.

Lastly in front of these defences were fixed, level with the ground, stakes one foot long armed with iron hooks called stimuli placed near each other, all over the space in front. Five have been found in the excavations.


[image ALT: An engraving of a portion of a wall of masonry in somewhat irregular courses of small stone blocks, the courses frequently interrupted by the ends of wooden logs. The logs extend into the wall and give it solidity. The masonry is part of a system of defensive fortification described in the text of this page.]

Fig. 24.


[image ALT: An engraving of a plan view of the previous image, in which the arrangement of logs within the wall is shown; they serve the purpose of reinforcement bars in today's concrete structures. The masonry is part of a system of defensive fortification described in the text of this page.]

Fig. 25.

From the Life of Julius Caesar. — Plate 20.

The Gaulish walls at Avaricum, represented in the accompanying woodcut, were made in the same manner as those seen in No. LVIII and in No. LXXXVIII, the last and greatest of the strongholds taken in the second Dacian war, as represented on the Column.

The walls in the Gaulish works are partly of earth with layers of timber logs laid at certain heights athwart the thickness of the wall as in the elevation in No. 24. They are held in the wall by longitudinal ties, as in the plan.  p55 The wall is thus faced with stones, and backed with earth, the whole firmly tied together by the timbers inserted at intervals. It would seem as if the same method had been used by the Dacians.

In the walls of the stronghold of Decebalus the walls between the rows of timberwork are faced with irregular masonry, such as is seen on a large scale in the old walls of Alatri, in the Apennines, and in other cities of antiquity, called cyclopean.​a If the stones are large, and if they are well cemented, on whatever scale, the irregularity of the shape does not prevent the construction of a wall of great strength and more difficult of attack by the falx or dragging hook of the ancients than if the stones were regularly coursed.

 p56  Gates


[image ALT: A set of five small schematic diagrams showing plan views of Roman gates and the walls immediately within them; these diagrams are explained in the accompanying text.]

Fig. 26.

The formation of the gates is seen in many of these sculptures. Gateways were recessed or covered by a projecting portion of wall, and then contrived to open in a line parallel, or at right angles with the wall, as in plans A, B, C, D, E, so as to be the more easily defensible from within. These plans are taken from those given in Caesar's camp on the Aisne, and they answer to the arrangements in many camps sculptured on the Column.

They were defended by doors or gates and clathra or fores clathratae, portcullises, — funibus ac catenis ita suspensae ut demitti et subduci possint, prout re postulat, quales in urbium aut arcium aditu, ostium irruptione propulsandâ in usum remanserunt.​61 In one of the gates of Pompeii the channels down which such doors were intended to be dropped can still be distinguished. They are frequently seen on the column.

According to Vegetius, the besieged provided themselves with horsehair, woollen cloths, &c. to protect the wooden defences from fire. Crates full of stones were placed between the pinnae or battlements.​62 Over the door the wall was to be provided with scuttle holes for pouring water down to extinguish attempts to fire the doors. Platforms for this purpose are frequent on the column. Amongst the stores required by the besieged were bitumen, sulphur, hot pitch, and oil; iron utriusque temperaturae, hard for weapons, soft for engines, hoop iron, &c., wood, nails, great wheels to let down and set on fire to run amongst the men and horses of the besiegers, timber in proper scantlings for the construction of spare machines. For the same objects, hides and horns, horses' hair, and the long hair of women were kept amongst the warlike stores of strong places, when these were properly provisioned for military operations.


The Author's Notes:

61 Maigne d'Arnis Lexicon med. et inf. Latinitatis, &c. in verb.

62 Vegetius, IV.6.º


Thayer's Note:

a Several good photographs, both general and detail, of the cyclopean walls of Alatri can be found on Roberto Piperno's excellent site.


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Page updated: 8 Sep 20