C—lα

Fig. No. 10.

Tension Apparatus. A. Three-quarter-inch galvanized-iron rod. F. Stay-pole. B. Foot-stand for stay-pulley. G. Stay-weight. C. Pulleys. H. Tripod with signal attachment for angular work D. Tension-wires. I. Extensions for legs of tripod. E. Tension-frame and screw for slow motion. Approximate strain put on K. Balance with grip attached. by sliding frame up or down rod.