In the year 1745, John Frederic Unger, then land-bailiff and burgomaster of Einbec, and who is known by several learned works, fell upon the same invention without the smallest knowledge of the idea published in England. This invention however, owing to the variety of his occupations, he did not make known till the year 1752, when he transmitted a short account of it, accompanied with figures, to the Academy of Sciences at Berlin. The Academy highly approved of it, and it was soon celebrated in several gazettes, but a description of it was never printed. A few days after Euler had read this paper of Unger’s before the Academy, M. Sulzer informed Hohlfeld of the invention, and advised him to exert his ingenuity in constructing such a machine. In two weeks this untaught mechanic, without having read Unger’s paper, and even without inspecting the figures, completed the machine, which Unger himself had not been able to execute through want of an artist capable of following his ideas. Unger’s own description of his invention was printed, with copper-plates, at Brunswick, in the year 1774, together with the correspondence between him and Euler, and other documents. A description of Hohlfeld’s machine, illustrated with figures, was published after his death by Sulzer, in the new memoirs of the Academy of Berlin, 1771, under the title of ‘Description of a machine for noting down pieces of music as fast as they are played upon the harpsichord.’ Sulzer there remarks, that Hohlfeld had not followed the plan sketched out by Unger, and that the two machines differed in this--that Unger’s formed one piece with the harpsichord, while that of Hohlfeld could be applied to any harpsichord whatever.