In another place the same historian writes of the English trade as follows:-- "The Pisans, Genoese, and Venetians supply England with the Eastern gems, as saphires, emeralds, and carbuncles; from Asia was brought the rich silks and purples; from Africa the cinnamon and balm; from Spain the kingdom was enriched with gold; with silver from Germany; from Flanders came the rich materials for the garments of the people; while plentiful streams of wine flowed from their own province of Gascoigny; joined with everything that was rich and pretious from every land, wide stretching from the Hyades to the Arcturian Star." No doubt this expansion was due, in part, to the very large participation which the English fleet took in the Crusade. Great numbers of English mariners were thus enabled to penetrate into seas that were new to them, and had opportunities of studying the commercial needs of the countries which bordered on those seas. Another cause which powerfully contributed to the development of navigation, and consequently of shipbuilding, was the introduction of the mariner's compass into Western Europe during the first half of the thirteenth century. The English war navy, also at the commencement of the reign of Henry II., appears to have been in a very efficient condition. Matthew Paris gives a description of a great naval fight off the South Foreland, in the year 1217, between a Cinque Ports Fleet under the famous Hubert de Burgh, who was at the time Governor of Dover Castle, and a large French fleet under a monk of the name of Eustace, who was one of the most skilful naval commanders of his day. The English fleet consisted of forty vessels, of which only sixteen were large and manned with trained sailors. The French fleet, which was endeavouring to carry a strong invading army to England, was made up of eighty large vessels, besides numerous galleys and smaller craft. The account of the battle is most interesting, because it throws a flood of light upon the naval tactics and the weapons of offence of the day. The English commander manoeuvred for the wind, and having got it, he bore down on the French fleet, and attacked their rear ships with flights of arrows carrying phials of unslaked lime, which being scattered and carried by the wind, blinded the Frenchmen; boarding was then attempted with perfect success, the rigging and halyards of the French ships were cut away, causing the sails to fall upon their crews. A hand-to-hand combat then took place, which resulted in fearful slaughter of the would-be invaders: several of the French ships were rammed and sunk by the English galleys, and in the end the whole of the hostile fleet, with the exception of fifteen vessels, was taken or sunk. This was one of the most momentous naval battles in English history, and is memorable as having furnished the first recorded instance of a battle having been preceded by manoevres to obtain the weather-gauge.