This instrument consists of a long, narrow box of very thin deal, about six inches deep, with a circle 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 bridges of a fiddle, and screwed up or relaxed with screw-pins. The strings must all be tuned to one and the same note, 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 Abbate Gattoni. He stretched seven strong iron wires, tuned to the notes 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 heard at a greater distance. FIREWORKS. We know full well the intense delight taken by boys in risking their limbs or their lives, especially when such risk is accompanied with noise. Boys always have done so, and always will do so in spite of the very best of advice or precautions. As, therefore, it is impossible to keep them from making noises, and endangering themselves, we have, in this article, endeavored to show them how to make as much noise as possible, with as little danger as possible. What is there that makes the most noise, and is most dangerous? Gunpowder, of course. Therefore, we have given descriptions of the best methods of employing this material, feeling quite sure that of accidents with gunpowder nine out of every ten are caused by ignorance. We knew a boy who lost the use of a thumb, and took all the skin off the palm of his right hand, by ignorant management of powder. He had read of blasting rocks, and nothing would satisfy him but blasting a bank. So he bored a deep hole in it with a stick, filled the hole with gunpowder, and then poked a lighted lucifer into the powder. The consequence was that his face was so scorched as not to be recognized, all his eyebrows and eyelashes, and most of his hair were burned off, while his right hand was injured, as has been already mentioned. Now that boy had been studiously kept out of the way of powder by female relatives, and was naturally profoundly ignorant of its effects. Had he been taught to handle it, he would not now be forced to keep his right hand closed, or to write by holding the pen between the fingers of his clenched hand. Gunpowder.