The clavones are again mentioned in the Wardrobe Accounts of King Edward I. in 1300[407]: "factura diversorum armorum, vexillorum, et penocellorum, pro Domino Edwardo filio Regis et Johanne de Lancastria, jamberis, poleyns, platis, uno capello ferri, una Cresta cum _clavis argenti_ pro eodem capello," &c. The chasto (Fr. _châton_) was a kind of socket or cavity, but the particular arrangement of it in fixing the crest has not been ascertained. About the same time we first hear of a defence for the horse of the nature of the later chanfrein. The same Windsor Roll of 1278 gives us the earliest notice of these "copita" of leather, made after the fashion (_de similitudine_) of horses' heads:-- "D Milōn le Cuireu͂r. xxxviij. copita co͂r de similitud' capīt equoȝ p'̄c pēc ij. s." They appear again in 1301, under the name of _testaræ_ (or _testeræ_) in the Indenture of Delivery of the Castle of Montgomery to William de Leyburn (Cott. MS. Vitell. C. x. fol. 154): "Item liberavit eidem iij. pa͂r coopertorum ferri et ij. Testaras et v. loricas cum capite et v. sine capite," &c. The thirteenth century appears to have retained all the ENGINES for the approach and attack of towns that were in use during the preceding age. In this century we first obtain pictorial evidence of the form and principle of the mangona or trebuchet of the middle-ages, and from this valuable testimony we learn that the motive power of _torsion_ employed during the classic period is no longer in favour; but instead, we have a machine from which, by means of a counterpoised beam, a large stone is cast forth from a sling fixed at one end of the beam. We have already (page 330) referred to the drawings of these instruments in an Arabic manuscript of this century, used by Captain Favé and M. Reinaud in their work, _Du feu grégeois, &c._ Other early representations occur in Roy. MS. 16, G. vi., copied in Shaw's "Dresses and Decorations;" in the ivory carving figured in the fourth volume of the Journal of the Archæological Association, and in the _Études sur l'Artillerie_ of the Emperor of the French, Vol. ii. Plate III. In the work of Gilles Colonne[408], written for his pupil, Philip the Fair of France, we have a distinct account of four varieties of the trébuchet: "Of pierriers," he says, "there are four kinds, and in all these machines there is a beam which is raised and lowered by means of a counterpoise, a sling being attached to the end of the beam to discharge the stone. Sometimes the counterpoise is not sufficient, and then they attach ropes to it, in order to move the beam. The counterpoise may either be fixed or moveable, or both at once. In the fixed counterpoise, a box is fastened to the end of the beam, and filled with stones or sand, or any heavy body. These machines, anciently called _trabutium_, cast their missiles with most exactness, because the weight acts in a uniform manner. Their aim is so sure that one may, so to say, hit a needle.