The article describes the treatment of structural metals used at the Boeing plane plant in 1929. Chrome-molybdenum and nickel steel tubing used in the fuselage are both heat treated. The former is heated to 1625 F, while the latter is heated to 1500 F. The length of treatment depends on the type and gage of tubing. The metal is quenched in oil, then treated a second time, at a lower temperature. Dural tubing and all aluminum and aluminum alloy parts are heat treated in potassium and sodium nitrate bath at 950 F. The process of assembling the fuselage on a jig is described briefly, including welding techniques used. In 1929, the largest fuselage being manufactured was a 50 foot long structure for the 18 passenger trimotor transport. The fuselage is covered with fabric and sheet dural. Exposed steel parts are plated with cadmium to combat corrosion.