The manufacture of plate-glass adds another to the thousand and one instances of the advantages of unrestricted and unfettered trade. The great demand occasioned by the immediate fall in price consequent upon the New Tariff, produced this effect on the Thames Plate Glass Works. They now manufacture as much plate-glass per week as was turned out in the days of the Excise, in the same time, by all the works in the country put together. The Excise incubi clogged the operations of the workmen, and prevented every sort of improvement in the manufacture. They put their gauges into the "metal" (or mixed materials) before it was put into the pot. They overhauled the paste when it was taken out of the fire, and they applied their foot-rules to the sheets after the glass was annealed. The duty was collected during the various stages of manufacture half-a-dozen times, and amounted to three hundred per cent. No improvement was according to law, and the exciseman put his veto upon every attempt of the sort. In the old time, the mysterious mixer could not have exercised his secret vocation for the benefit of his employers, and the demand for glass was so small that Mr. Blake's admirable polishing machine would never have been invented. Nor could plate-glass ever have been used for transparent flooring, or for door panels, or for a hundred other purposes, to which it is now advantageously and ornamentally applied. Thanking the courteous gentlemen who had shown us over the works, we left Mr. Bossle in close consultation with the manager. As, in crossing the yard, we heard the word "soda!" frequently thundered forth, we concluded that the Johnsonian drysalter was endeavoring to complete some transactions in that commodity, which he had previously opened with the director. But, it is not in our power to report decisively on this head, for our attention was directed to two concluding objects. First, to a row of workmen--the same we had lately seen among the fires and liquid glass--good-humoredly sitting, with perfect composure, on a log of timber, out in the cold and wet, looking at the muddy creek, and drinking their beer, as if there were no such thing as temperature known. Secondly, and lastly, to the narrow passages or caves underneath the furnaces, into which the glowing cinders drop through gratings. These looked, when we descended into them, like a long Egyptian street on a dark night, with a fiery rain falling. In warm divergent chambers and crevices, the boys employed in the works love to hide and sleep, on cold nights. So slept DE FOE'S hero, COLONEL JACK, among the ashes of the glass-house where _he_ worked. And that, and the river together, made us think of ROBINSON CRUSOE the whole way home, and wonder what all the English boys who have been since his time, and who are yet to be, would have done without him and his desert Island. "BIRTHS:--MRS. MEEK, OF A SON."--A PLEA FOR INFANTS.