We must, in conclusion, speak of the monochord (_monocordium_), which is always mentioned by the authors of the Middle Ages with feelings of pleasure, although it appears to have been nothing more than the most simple and primitive expression of all the other stringed instruments (Fig. 201). It was composed of a narrow oblong box, on each end of the front-board were fixed two immovable bridges supporting a metallic string stretched from one to the other, and corresponding to a scale of notes traced out on the instrument. A movable bridge, which was shifted up and down between the string and the scale, produced whatever notes the performer wished to bring out. In the eighth century there was a kind of violin or mandolin furnished with a single metallic string played on with a metallic bow. Later still, we find a kind of harp formed of a long sounding-box traversed by a single string, over which the musician moved a small bow handled with a sudden and rapid movement. The instruments we have named do not, however, embrace all those in use in the Middle Ages and the Renaissance. There certainly were others which, in spite of the most intelligent investigations, and the most judicious deductions, are now known to us only by name. As regards, for instance, the nature and appearance of the _éles_ or _celes_, the _échaqueil_ or _échequier_, the _enmorache_, and the _micamon_, we are left to the vaguest conjectures. [Illustration: Fig. 202.--Triangle of the Ninth Century. (MS. of Saint-Emmeran.)] PLAYING-CARDS. Supposed Date of their Invention.--Existed in India in the Twelfth Century.--Their connection with the Game of Chess.--Brought into Europe after the Crusades.--First Mention of a Game with Cards in 1379.--Cards well known in the Fifteenth Century in Spain, Germany, and France, under the name of _Tarots_.--Cards called _Charles the Sixth’s_ must have been _Tarots_.--Ancient Cards, French, Italian, and German.--Cards contributing to the Invention of Wood-Engraving and Printing. The origin of playing-cards has for many years past formed a special subject of investigation among scholars and antiquarians. For, however trifling the matter may appear in itself, this curious point is connected with two of the most important inventions of modern times--engraving and printing. We must not, however, take upon ourselves to assert too positively that all the profound researches, persevering study, and ingenious deductions which have been applied to the subject have entirely succeeded in elucidating the question. Nevertheless, a certain degree of light has been thrown upon it, by which we shall endeavour to profit.