A correspondent desires us to give him some particulars of this instrument, and directions how to construct it ; and as the summer is coming on, and its melancholy music may find many who will enjoy it during the hot season, we give the desired information for the benefit of all our readers :— This instrument consists of a long narrow box of very thin pine, about six inches deep, with a circla in the middle of the upper side, of an inch and a-half in diameter, in which are to be drilled small holes. On this side seven, ten, or more strings of very fine catgut are stretched over bridges at each end, like the bridge of a fiddle, and screwed up or relaxed with screw pins. The strings must all be tuned to one and the same note, (D is, perhaps, the best,) and the instrument should be placed in a window partly open, in which the width is exactly equal to the length of the harp, with the sash just raised to give the air admission. When the air blows upon these strings with different degrees of force it will excite different tones of sound. Sometimes the blast brings out all the tones in full concert, and sometimes it sinks them to the softest murmurs. A colossal imitation of the instrument just described was invented at Milan in 1786, by the Abb Gattoni. He stretched seven strong iron wires, tuned to the note of the gamut, from the top of a tower sixty feet high, to the house of a Signor Moscate, who was interested in the success of the experiment, and this apparatus, called the " giant's harp," in blowing weather yielded lengthened peals of harmonious music. In a storm this music was sometimes heard at the distance of several miles.