their capital to mine, and the works would have been started. But it is difficult to impress one's ideas on others, and I desired to have the personal and entire conviction of its value on the part of all those I asked to join me in the enterprise; without this I was resolved not to move further in the matter, and failing to obtain it, the whole scheme was abandoned.

There is one point in connection with patented inventions upon which I have always felt strongly. I have maintained that the public derive a great advantage by useful inventions being patented, because the invention so secured is valuable property, and the owner is necessarily desirous of turning that property to the greatest advantage; he either himself manufactures the patented article, or he grants licenses to others to do so. In either ease the public reap the advantage of being able to purchase a better or a cheaper article than was before known to them, due to the inventor's perseverance in forcing his property upon the market. But if a novel article or manufacture is simply proposed by a writer, and published in the technical press or in newspapers, as a rule (almost without a single exception) no manufacturer will go to the trouble and expense of trying to work out the proposed invention. He says to himself: "I shall not risk the expense necessary to develop this new idea, for it may entirely fail; or even if I succeed, its development will cost me much more than it will cost other manufacturers, who will immediately avail themselves of it if I succeed; no, let some one else try it;" and so the invention is lost to the world in consequence of having been given away. This loss to the public is equally the case with patents that are not taken up; and one of the simplest and most effective inventions which I ever made may be here cited as an example, as it formed part of the novel system of plate-glass manufacture just referred to. When a sheet of plate glass some 10 ft. or 12 ft. long and 6 ft. or 7 ft. wide has been ground perfectly flat on both sides, it is still dull and grey, and has to be polished. For this purpose it is usual to fix it firmly on to a large stone polishing table, so that the powerful alternate pushing and pulling of the polishing rubbers over its surface may not break or displace the sheet. To do this a large quantity of plaster-of-Paris is mixed with water, and spread as quickly as possible over the surface of a stone table much larger than a billiard table. Then the sheet of glass is dexterously laid upon the semi-fluid plaster, and carefully bedded by expert workmen so as to be well supported at all parts of its extensive surface; the superfluous plaster lying beyond the edges of the plate of glass is then scraped away. The polishing machine must remain idle until the plaster is sufficiently firm and hard to retain the glass safely in place. Care must also be taken to thoroughly remove all smears of plaster around the edges and any splashes on the surface, for the plaster is always more or less gritty, and one or two particles of sharp grit will play havoc with the polished surface, scratching it terribly. Let us suppose that one side of the great glass sheet has been polished. It is then necessary to unbed it, and this requires much skill. A man at each corner inserts a thin blade of steel and gently prises the sheet up; he must not spring it much, or the corner will snap off, and considerably diminish the size of the sheet when squared up. With much risk and trouble, the plate of glass is eventually released, and lifted off the stone bed; then the workmen proceed to chip off the hard plaster which firmly adheres to the table. This makes a great mess all round the polishing machine by the flying about of chips of plaster. The stone table having been chipped all over, and scraped quite clean, a fresh lot of plaster is again mixed up, dexterously spread, and the sheet of glass, with its unpolished surface uppermost, is again bedded on the table, and all superfluous surrounding plaster carefully cleared away. Again the powerful polishing machine remains inactive, until the sheet of glass is firmly stuck to the bed, and, after polishing, the same dangerous process of springing the glass loose from the table has to be repeated. After its removal, the bed has to be chipped all over, and the hard coating of the plaster-of-paris removed, for the reception of another plate.

Such is the laborious, dirty, and risky process to which every sheet of plate glass is subjected in the ordinary course of its manufacture. Now let us see what was the simple mode which I patented of holding down a sheet of plate glass securely during the polishing process. I employed (see Figs. 29 to 32, page 120) a cast-iron ribbed plate of the size of the polishing stone table, on the upper side of which a large slab of slate (such as is used for billiard tables) was supported and bedded on the ribs of the iron plate. This surface was then ground flat, in the same manner as plate glass, the space beneath the slate and between the iron ribs forming a shallow box. A number of round holes of about a quarter of an inch in diameter were made through the slab of slate all over its surface, at a distance of 4 in. or 5 in. apart, so that air could enter the iron box freely from all parts of its surface; a pipe of 1 in. in diameter led to a