_Son._ Inasmuch as you seem to think that you have described most of the weapons which are convenient to have in naval warfare or in fighting on horseback, I will now ask you to say something about those which you think are most effective in besieging or defending castles. _Father._ All the weapons that we have just discussed as useful on ships or on horseback can also be used in attacking and defending castles; but there are many other kinds. If one is to attack a castle with the weapons which I have enumerated, he will also have need of trebuckets:[272] a few powerful ones with which to throw large rocks against stone walls to determine whether they are able to resist such violent blows, and weaker trebuckets for throwing missiles over the walls to demolish the houses within the castle. But if one is unable to break down or shatter a stone wall with trebuckets, he will have to try another engine, namely the iron-headed ram,[273] for very few stone walls can withstand its attack. If this engine fails to batter down or shake the wall, it may be advisable to set the cat[274] to work. A tower raised on wheels[275] is useful in besieging castles, if it is constructed so that it rises above the wall which is to be stormed, even though the difference in height be only seven ells; but the higher it is, the more effective it will be in attacking another tower. Scaling ladders on wheels which may be moved backward and forward are also useful for this purpose, if they are boarded up underneath and have good ropes on both sides. And we may say briefly about this craft, that in besieging castles use will be found for all sorts of military engines. But whoever wishes to join in this must be sure that he knows precisely even to the very hour when he shall have need for each device. Footnote 272: The trebucket (French _trébuchet_) was a siege engine which came into use in the twelfth century; it was worked by counterpoises. For a description see Oman, _Art of War_, 143-144; _Aarböger for nordisk Oldkyndighed_, 1867, 103-104; Falk, _Altnordische Waffenkunde_, 193-194. Footnote 273: The ram was a massive beam used to batter down walls; it was an inheritance from antiquity and was much in use. See Oman, _Art of War_, 132; _Aarböger for nordisk Oldkyndighed_, 1867, 104; Falk, _Altnordische Waffenkunde_, 198. Footnote 274: _Grafsvin._ Falk translates this with “badger” and seems to believe that it was a shelter on wheels under which the attackers might work in comparative safety. _Altnordische Waffenkunde_, 196. It is more likely, however, that a “cat” is meant. The cat was a long pointed pole used to loosen the stones in a wall and thus to make a breach. It is also called a “sow” and the Old Norse term _grafsvin_, “digging boar,” was evidently an attempt to translate the Latin term _scrofa_ or _sus_, “hog” or “sow.” For a description of the cat, see Oman, _Art of War_, 132. Footnote 275: