"One of the quickest repairs on record was accomplished on the Mississippi River Steamship ' Betsy Ann/ belonging to Learned & Son, Natchez, Miss. This is a stern wheel boat, the shaft being a hexagonal one, 83/5 inches on the inscribed circle and over 23 feet long. A crack developed on one of the faces and ran down a short way on the second face, the total length visible being about 4 inches. Attention was first called to this by rust showing through the paint and after examining the shaft carefully it was decided to run the steamer to see if the crack extended. Within a short time it was noticed that the crack had extended 3/4 inch since the first observation, and it was therefore decided that a repair of some sort should be made on it at once. Preparations were made to weld a collar of Thermit steel around the shaft at the fracture and thus to restore it to its original state of usefulness. A pneumatic chipping hammer was used for cutting away the metal to the bottom of the flaw, so that the superheated Thermit steel could be led to the deepest part. After this had been accomplished, the paint was cleaned off a distance of 5 inches on either side of the fracture and the weld effected by the wax pattern method, as previously described; 416 pounds of Thermit, 35 pounds of mild steel punch-ings, and 8 pounds of metallic manganese being required. After allowing five hours for the metal to set, the mold box was removed and the weld found to be so satisfactory that the steamer immediately proceeded on her trip without waiting for the gate and riser to be cut off; in fact, the repair was accomplished without causing the steamer to miss a single trip."

1 Ibid., Jan. 28, 1905.

2 Iron Age, Nov. 16, 1905.

3 Reactions, published by Goldschmidt Thermit Co.

Fig. 83. - Finished weld of S. S. "Betsy Anne" before removing metal left in gate and riser.