Scope and ContentEnvelope imprinted for Professor Charles F. Kroeh, Stevens Institute of Technology, promoting language books for which he was the author and publisher, ca. late 1880s or early 1890s. The postage envelope or postal stationery has an embossed one-cent blue oval Franklin (considered as Scott U294, issued 1887-1894) and is imprinted in black: Prof. Chas. F. Kroeh Stevens Institute of Technology, Hoboken, N.J. Publisher of How to Think in French How to Think in German How to Think in Spanish etc., etc. ==== Kroeh was a professor of modern languages.