During the years that followed he constantly improved the quality of his lenses and the accuracy and speed with which he could “execute the true curves,” as he expressed it. He used better and better glass. In his early experiments he had taken what came to hand—ordinary tumbler bottoms, for instance. In his 1845 prize winner he combined Boston-made flint with French plate glass. But the Boston flint proved too veiny for any but small lenses and he soon was importing both crown and flint. He designed and built machines, run by foot power, on which he could train employees to do much of the labor of lens making, always reserving the final polishing for himself. He increased the size as well as the quality of his lenses. By 1856, he was making 12½-inch refractors, which according to Prof. Loomis, were as large as any that had then been made in Munich. He built later, still larger ones, of which one was a 16-inch instrument made for Mr. Van Duzee of Buffalo. It was his ambition to make a 24-inch one, but this project, for which he had made careful plans, he did not live to complete. One of his early successes was a 3¾-inch telescope for the Government of Haiti. By a happy accident the objective for this instrument proved to be exceptionally fine and provided a standard which he tried to meet in all his work. The telescopes of European opticians became another measuring stick. It was a matter of both personal and patriotic pride to him that he, an American locksmith untrained in optics, had been able to invent his own process for making so complex and difficult a thing as an achromatic lens, and that he was able to manufacture telescopes to compete with those of European make. He sometimes contracted to make a telescope equal in performance to an imported one of similar size, usually at a lower price. The 6¾-inch telescope made in 1849 for Lt. J. M. Gilliss to use on an astronomical expedition to Chile passed such a test and greatly enhanced Henry Fitz’s reputation. Another that met such a test was the 13-inch instrument made for the Allegheny Association at Pittsburgh in 1861. His telescopes were procured by private observatories not already mentioned, among them that of Van Arsdale, in Newark, and of Campbell, in New York. For Rutherfurd he made several, including a 9- and a 12-inch instrument. The latter is now at Columbia University. Among the telescopes made for colleges were a 12-inch one for Vassar and another for the University of Michigan. Besides these and other important instruments he made many of smaller size—4, 5, 6, and 8 inches.