Fowler’s Patent Model of a Furnace Steam Boiler - ca 1856

This model was filed with the application to the U.S. Patent Office for Patent Number 15,803 issued to David H. Fowler of New Orleans, Louisiana on September 30, 1856. Mr. Fowler’s patent was for a new design for a boiler with both internal and external flues . The goal of the two flues was to increase the amount of boiler surface area exposed to the hot combustion gases from the furnace. His design called for a central boiler that was mounted above the furnace. The three supporting legs for the boiler surrounded the furnace and were tubes that allowed the introduction of water into the boiler via the legs. The internal flue passed through the center of the boiler and was surrounded by the water. Combustion gases flowed upward through this flue, transferring heat to the water. The external flue was implemented via a four inch space between the boiler’s side and the surrounding brickwork. This space ran around the entire circumference of the boiler. This allowed a portion of hot combustion gases to also heat the external wall of the boiler, significantly increasing the surface area of boiler metal being exposed to the gases. The external flue was capped at the top of the brickwork, and horizontal openings were provided at regular intervals around the circumference which communicated with the external flue. The chimney was located above the external flue, and a separate pipe connected the internal flue to the external. In 1861 Mr. Fowler advertised as a Steam Boiler Manufacturer in New Orleans. Research of available trade literature and other sources has not revealed any additional commercial use that may have made use of Mr. Fowler’s invention.