JACOB, an eminent engraver, was the son of Arnold Houbraken, a native of Holland, and was born Dec. 25, 1698. For some time he worked in obscurity, and had attained the meridian of life before he engaged in the undertaking by which he is best known; a work founded on a plan of George Vertue, who proposed a series of engravings of the greatest men of ancient and modern times. The persons who brought out this great national work were the Knaptons, who employed both Vertue and Houbraken, but chiefly the latter. Some of Houbraken's heads were carelessly executed, especially those of the moderns; but others display a wonderful union of softness and freedom, with good drawing, and a masterly determination of the features, such as are shown in the works of Nanteuil, Edelink, and Drevet. In his desire to avoid the appearance of an outline, he frequently neglected the little sharpnesses of light and shadow which appear in nature, and please, like the accidental semitones in music, in proportion as the variation is judiciously managed. For want of attention to this essential beauty, many of his prints have a hazy appearance, and do not strike the eye with the force which might be expected from the excellence of the engraving. Houbraken lived to a good old age, and died at Amsterdam in 1780. No complete set of Houbraken's prints is now extant, in this country at least. The last that was known to exist was the property of the Duke of Buckingham, but it was broken up and dispersed at the great sale at Stowe in 1848.