General Engineering Company Building
159 West Pierpont Avenue in Salt Lake City, Utah (National Register #80003922)

The significance of the General Engineering Company building lies in its close association with the company’s founder, John Michael Callow, a successful inventor and internationally recognized mining engineer and metallurgist. Callow not only worked and produced his inventions at this location, but he and his family lived on the premises for 26 years. The building symbolizes:; the importance to the western mining industry of John Michael Callow, who helped overcome many of the problems associated with low grade ore treatment and thus stimulated the growth and development of mining in areas previously considered economically marginal.

Callow was born in England, but moved to the United States in 1890. He gained his initial experience of western mining in mines and mills in San Juan County, Colorado. In 1900 Mr. Callow moved to SLC with his family, and remained a resident until he returned to England to retire in 1933. Callow is best known for originating the pneumatic flotation process in treating ores, although he was the holder of a total of 18 patents relating to innovations in mining technique. In 1912 he was responsible for the design and construction of the pioneering National Copper Company plant in Mullan, Idaho, which incorporated his flotation cells.

Callow was a prominent member of the American Institute of Mining and Metallurgical Engineers, which honored him in 1926 with its highest award for achievement…the Douglas Gold Medal Award. He was also a member of the Metallurgical Society of America and the Colorado Scientific Society.

The presence of the General Engineering Company building is not only a reminder of the work of Callow, but also of the great importance of mining and mining supported industries to the growth and development of Utah.

Thus, the buiding boasts of a unique past, mixing both the commercial-industrial and private residential environments. It is worthy of all efforts to preserve and restore its place in regional and national prominence.

The building is 22′ x 100′ with exposed brick facing on the east side and rear of the building, with a party wall on the west side, and a stucco finish on the front. On the façade of the building are the raised letters GENERAL ENGINEERING CO., in letters approximately 9″ high. The inside of the building consists of 3 floors, all of which have been cleared of partitions so as to accommodate the installation of modern conveniences and transformation to modern uses. The external appearance of the building is said to be the same as when first constructed.