There is but little information to be obtained regarding the actual materials used by the armourer. The chief source from which he drew his supplies seems to have been Innsbruck. Why this was so is not clear from the contemporary records, but we may be sure that the German metal was harder and better tempered than that of other countries, or there would not have been the demand for it that there evidently was. In the various entries in the State Papers Domestic we find specific mention of “Isebruk” iron, and the merits of this metal must have been appreciated even in Shakespeare’s time, for we have in _Othello_, v. 2, 253, “a sword of icebrook’s temper.” In the earliest editions of the play the word is “Isebrooke,” which is obviously the anglicized version of Innsbruck.[61] Sheffield steel must have been appreciated as early as Chaucer’s time, for the Miller carries a “Sheffield thwyrtel” (knife), and in 1402 the arrows used at the battle of Homildon were pointed with Sheffield steel, so sharp that no armour could repel them. It is possible that the German iron-smelters had discovered the properties of manganese, which hardens steel, and thus obtained a superior metal to that produced in other countries. The discovery of steel was probably a fortuitous accident, due to the fact that the first smelting-works were fuelled with charcoal, which deoxidizes iron and turns some portion of the metal into natural steel. The Germans themselves realized the superiority of their material, for in 1511 Seusenhofer complained that his merchant was not giving him good metal, and advised that it should be classed as “Milanese,” so as not to lessen the fame of Innsbruck iron. Till the seventeenth century English iron seems to have been largely used for domestic purposes, for we find on examining Professor Rogers’s _Agriculture and Prices_ that German iron is never mentioned, but there are frequent references to English and Spanish metal. The following prices from the above work show the fluctuations in prices of iron in England. 1436. Spanish iron, 24 lb., 1s. 6d., or about £14 the ton. 1462. Iron, 42 lb. at 5d., or £17 10s. the ton. 1562. Raw English iron, £12 10s. the ton. Bilbow (Bilboa), £11 8s. the ton. Spanish, £12 the ton. 1570. Iron gun-stocks, made up, £28 the ton. 1571. Steel bar, £10 the ton. Bar steel, £37 4s. the ton. 1584. Spanish iron, £14 the ton. 50 bars to the ton, or about 45 lb. to the bar. 1622. Steel, £32 the ton. 1623. Spanish iron, £14 10s. to £15 10s. 1624. Iron bars of 24 lb. at £37 4s. the ton. These prices vary so greatly that we must be sure that there was a great difference in the quality, and also in the state in which the metal is delivered. In some cases there must have been a great deal of preparation and finishing of the raw material to account for the high price paid.