Hemingray was Chapter 23 of the American Flint Glass Workers' Union. They were the largest chapter and, from some readings of AFGWU papers, seem to be the only AFGWU chapter making insulators a lot (Most? All?) of the time.

If you were one of those workers, here are your wages and the rules you worked under: Four separate pages.

Source: Engraving department / Wage list / Adopted at the Joint Conference held at Atlantic City, N.Y. 1916 To continue in Effect Until June 30, 1917 / American Flint Glass Workers Union of North America