David Lennox (April 15, 1855 – February 15, 1947) was an American inventor and businessman. A furnace manufacturing business he founded in 1895 in Marshalltown, Iowa evolved into what is today known as Lennox International, a global corporation specializing in air conditioning, heating, and commercial refrigeration. Lennox helped to develop what has been described as the first riveted-steel furnace in 1895. His contributions to furnace design have been described as significant steps forward in durability and efficiency from the cast iron furnaces commonly in use near the end of the 19th century. Early life Born in Detroit, Michigan on April 15, 1855, Lennox was the son of a railroad mechanic. His family moved to Aurora, Illinois shortly before the American Civil War, where Lennox’ father enlisted in the Union Army. His father was killed in 1863 at the battle of Champion Hill, east of Vicksburg, Mississippi. The surviving Lennox family moved to Chicago in 1865, where Lennoxs’ mother ran a grocery store while he worked in various machine shops. David Lennox moved to Marshalltown, Iowa in July, 1881, where he initially was hired by the Iowa Steel Wire Company to make barbs for their barbed wire fencing. He fabricated a custom machine to cut the steel barbs and soon afterwards started his own blacksmith and machine shop. Lennox designed a staple-cutting machine for Ed Sears, a local businessman, well drills that were used to penetrate deeper into the ground, also developed new designs for trowels in which the Marshalltown Company was founded, heavy-duty shears, and other tools. Furnace business In 1895, Ernest Bryant and Ezra Smith, two businessmen from Oskaloosa, Iowa, shared with Lennox their plans for a furnace using riveted steel for the heating surface. The furnaces used to heat homes at that time were made entirely of cast iron, which had a tendency to warp and crack after extended use and could cause smoke and coal gases to seep into houses. Bryant, Smith, and Lennox entered into an agreement in which Lennox made the iron castings used for the grates, fronts, and other parts of their steel furnaces. When Bryant and Smith were unable to pay Lennox for the iron castings after losing their financial backing, Lennox took over their patents and reworked their original design. Marketing the furnaces under his own Torrid Zone brand name, Lennox' furnace business grew and became a success. Lennox sold his furnace