Cloth is used for a variety of purposes in the establishment of Messrs. Boardman & Gray. It is made and prepared expressly for their use, from fine wool, of various thicknesses and colors, according to the use for which it is designed. Whether its texture be heavy or thick, firm or loose, smooth or even, soft or hard, every kind has its peculiar place and use. Here we would give a word of caution to the reader. So much cloth is used in and about the action of the piano-forte, that we must beware of the insidious moth, which will often penetrate and live in its soft folds, thereby doing much damage to the instrument. A little spirits of turpentine, or camphor, is a good protection against them. Ivory is another article which is largely used. Being expensive, no little capital is employed in keeping an adequate supply at all times on hand. And then there is buckskin of various kinds and degrees of finish, sand-paper, glue, and a variety of other things, all of which are extensively employed in the business. So far, we have treated merely of materials and labor. We have said nothing of the science of piano-forte making. If, after all the pains taken in selecting and preparing the materials required, the scale of the instrument shall not be correctly laid down on scientific principles; that is to say, if the whole is not constructed in a scientific manner, we shall not have a perfect musical instrument. So the starting-point in making a piano-forte is in having a scale by which to work. This scale must be of the most improved pattern, and laid out with the utmost nicety, and with mathematical precision. By the scale, we mean the length of each string, and the shape of the bridges over which it passes. The length of the string for each note, and its size, are calculated by mathematical rules, and perfected by numerous experiments; and by these experiments alone can perfection be attained in the manufacture of the instrument. Messrs. Boardman & Gray use new and improved circular scales of their own construction, in which they have embodied all the improvements which have from time to time been discovered. They are determined that nothing shall surpass, if anything equals, their DOLCE CAMPANA ATTACHMENT. [Illustration: VIEW OF ONE OF BOARDMAN AND GRAY'S ORNAMENTAL FINISHED PIANO-FORTES.]