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98 turning the handle of the machine, until breakage of the paper takes place. The machine registers the strain put upon the strip, and also the elongation which the strip sustained before fracture. The Marshall machine takes strips of various lengths and widths, and registers the tension on a hydraulic pressure gauge, the stretch being measured exactly and calculated on the length of the strip used. Leunig's testing machine

registers breaking strain and stretch on two scales. The strip, ⅝ inch wide, is clamped between two clips 7 inches apart, and, by turning a handle, the strip under tension raises a weight at the end of a lever. The strain exerted by the weight is indicated on a scale marked in quarter-pound divisions. The stretch is registered at the same time by a pointer actuated by a separate rack. The stretch scale and pointer are