“ Among the manufactures are zinc spelter—there are large smelters here—clay products (chiefly vitrified brick, sewer pipe and tile; the clay being obtained from a great underlying bed of shale) , blasting powder, packing-house products and planing-mill products. The total value of the city's factory products in 1905 was $1,824,929. Pittsburg was settled about 1879, was chartered as a city in 1880, and became a city of the first class in 1908. ”