The modern format of the hyphen originated with Johannes Gutenberg of Mainz, Germany, with the publication of his 42-line Bible. His tools did not allow for a hyphen, and he thus moved it to the middle of the line. Examination of an original copy on vellum (Hubay index #35) in the U. S. Library of Congress shows that Gutenberg's movable type was set justified in a uniform style, 42 equal lines per page. The Gutenberg printing press required words made up of individual letters of type to be held in place by a surrounding non-printing rigid frame. Gutenberg solved the problem of making each line the same length to fit the frame by inserting a hyphen as the last element at the right-side margin. This interrupted the letters in the last word, requiring the remaining letters be carried over to the start of the line below. His double hyphen appears throughout the Bible as a short, double line inclined to the right at a 60-degree angle: