As I mentioned earlier, when I first came here I thought that the industry had died because there was no more raw material and they had to give it up. But such was not the case. If Rosendale cement were made today there’d be none better in the world for brick and stone masonry, if it’s used in a thin layer. The masons loved it. They would put it on their trowel, turn the trowel upside down, or slice the cement onto a brick and hold the brick upside down. The cement was so adhesive that it wouldn’t slide off and drop to the ground. They loved it. But if Rosendale cement is used in a mass, in concrete, it takes forever to set. It won’t harden fast enough. When skyscrapers began to be built in New York City — and the Flatiron Building was the first, about 1900 — they’d pour a cement floor with Rosendale cement and it would take four to six weeks for that cement to get to full strength before they could go up another floor. But the contractors were in a hurry and didn’t want to wait that long.
Meanwhile, the process of making Portland cement — mixing limestone, clay, shale, magnesium, and other chemical additives — was discovered in England in 1890. When the contractors in this country heard of this new Portland cement which would harden in only 24 hours they all wanted it. So the Rosendale cement industry tried to make Portland cement with this new process but it didn’t work. There’s something inherent in Rosendale limestone which precluded it and, try as they would, they couldn’t make Portland cement out of Rosendale limestone. But there was a limestone deposit discovered in eastern Pennsylvania, near Bethlehem, which was conducive to making Portland cement. And when they started making Portland cement in Pennsylvania they stole the market! All the contractors wanted the new style, fast-setting Portland cement.