Indiana University Libraries Book Repair Manual
MEASUREpHASE
This tool is used to measure books, chiefly for the purpose of constructing enclosures for them. It yields accurate overall measurements of three-dimensional objects such as books, in that it measures between two surfaces perpendicular to the tool's table, on which the item being measured is placed. Thus, it measures much in the manner of a vernier caliper, or a "shoe sizer" (by which nickname it is sometimes called).