From the mountain of cork unloaded at its doors a host of different articles are produced by means of wonderfully ingenious machinery coupled with hundreds of keen brains, for the human element must always play a large part in cork manufacture. Among them corks rank first in importance; hence the greater part of the floor space of this factory, the largest of its kind in the world, is given over to their production. [Illustration: Slicing into Strips] [Illustration: Bales of Cork being unloaded at Pittsburgh] For whatever purpose it is to be used, all bark removed from the immense storage rooms is taken first to the sorting department, where, under skilled eyes, the twenty-five or more foreign grades are resorted into approximately one hundred and fifty different classes, according to quality and thickness. The speed and skill with which this work is done is astounding. So slight is the difference between some of the grades that to the inexperienced eye none can be seen whatever, and yet success hinges on the care and skill exercised in this and the other sortings that follow. [Illustration: Corks punched from Strips] [Illustration: One of the Fourteen Storage Rooms, Pittsburgh Factory] [Illustration: Cork Punchings] [Illustration: One of the Corkwood Sorting Rooms at Pittsburgh] [Illustration: Cutting into Squares] In manufacturing corks it must be understood in the first place that the thickness of a given piece of bark determines the maximum diameter of the stopper which can be made from it, as the cutting is done across and not with the grain. Leaving the sorting room the corkwood is softened by placing it in a warm vapor bath. This process increases its flexibility greatly, its bulk slightly, and prepares it to undergo the various mechanical operations which follow in rapid succession. The keen edge of the slicer first confronts the sheets of bark, and it is at this point that the first mechanical obstacle in cork manufacture has to be overcome, for the soft, light, elastic material is, withal, very difficult to cut, as may be determined by simple personal experiment. But before the onslaught of a circular steel knife, revolving hundreds of revolutions every minute and kept at razor-like sharpness, even this difficulty disappears, and the sheets are readily cut into strips whose width is determined by the length of the cork desired. From the slicer the strips pass to the blocking machines, where, by means of a rapidly rotating tubular punch, cylindrical pieces are bored out and released with almost incredible speed. The operative, of course, must use care to avoid defective spots in the bark, and also to cut the corks out as closely together as possible so as to reduce waste to a minimum. The stoppers which come from these machines are round with parallel sides. If tapered corks are desired, larger at the upper end than at the lower, the cylindrical or “straight” pieces must be passed through another machine, which