A Business Fact.—The mechanical engravings that embellish the weekly issues of the SCIENTIFIC AMERICAN are generally superior to those of any similar publication, either in this country or in Europe. They are prepared by our own artists, who have had long experience in this branch of art, and who work exclusively for us. There is one pertinent fact in connection with the preparation and publication of an illustration in our columns that needs to be better understood by many inventors and manufacturers who pursue a shortsighted policy in bringing their improvements to public notice. They often go to a large expense in printing and circulating handbills, which few care either to read or preserve. Now, we undertake to say that the cost of a first-class engraving, done by our own artists, and printed in one issue of the SCIENTIFIC AMERICAN, will amount to less than one half the sum that would hava to be expended on a poorer illustration printed in the same number of circulars, and on a sheet of paper in size equal to one page of our journal. A printed handbill has no permanent value. Thousands of volumes of the SCIENTIFIC AMERICAN are bound and preserved for future reference—beside, we estimate that every issue of our paper is read by no fewer than one hundred thousand persons. Considered, therefore, as a mere advertisement, an illustration in the SCIENTIFIC AMERICAN is a paragon of cheapness. ACCORDING to the Tribune, everything at the approaching Boston Musical Peace Jubilee, promises to be upon a lovely scale of largeness. The big drum to be used upon the occasion has been finished, and O'Baldwln, the Irish giant, has also been engaged to beat it. This mastodonian drum is three feet through from head to head; the heads are about eight feet in diameter ; for the skins, two mammoth oxen yielded up their hides, it being found impossible to procure the hide of an elephant, and upon each head is ironically painted " Let Us Have Peace !" Whether this drum will make any more noise than six smaller ones beaten in unison we do not know, but we are sure that it will cut a much larger figure in the advertisements. A COMFORTABLE CHAIR,.—Mr. F. A. Sinclair, of Mottville, K.Y., has sent to this office a specimen of the chairs made at his manufactory, which, he says—and we believe him—meets the requirements of a recent inquirer in the American Builder for R, good chair. The specimens received are of the same primitive style as those of the days of our grandmother. The Seats are of split ash, very capacious in size, and the chair, with its high arms and easy-fitting back, is a perfect embodiment of comfort.