Mambourg Glass Company was a window glass manufacturer that began production on October 26, 1887. The company was the first of thirteen glass manufacturers located in Fostoria, Ohio, in the United States, during northwest Ohio's gas boom. The plant was managed by Leopold Mambourg, a Belgian immigrant and experienced glassmaker. Much of the company's work force was also from Belgium. Former Ohio governor Charles Foster was president of the company and a major financial backer. He was also a major investor in other businesses and two additional Fostoria window glass companies: the Calcine Glass Company and the Crocker Glass Company. Mambourg was the chief operating officer for all three of Foster's window glass companies.
The startup for Mambourg Glass Company went well, and the company was busy producing high quality window glass. A capacity expansion was finished in January 1890. The company continued to hire glassworkers from Belgium to meet its need for more skilled workers. By mid-1891 the plant, and other factories in Fostoria, was plagued by fuel shortages as northwest Ohio's natural gas that was used to power the glass company furnaces began to be depleted.
In the summer of 1892, Leopold Mambourg left town to start another glass company near Columbus, Ohio. During the Panic of 1893 Foster could no longer meet his financial obligations. In May his three window glass companies were closed and Foster assigned control of the three companies (and others) to his creditors. The Mambourg Glass Company plant was leased from the creditors and restarted in December 1893 as an employee-owned co-op. However, after it closed for the summer stop on June 19, 1894, it never reopened.
Background
Window glassmaking in the 1880s
Glass is made by starting with a batch of ingredients (mostly sand), melting it, forming the glass product, and gradually cooling it. The batch is placed inside a pot or tank that is heated by a furnace to roughly 3090°F (1700°C). During the 1880s, window glass was made using the hand–blown cylinder glass method. A crew led by a glassblower started the process of shaping the glass. A gatherer removed a glob of molten glass (called a gob) from the furnace using a blowpipe. The blowpipe, with its gob, was then passed to a glassblower, who would blow into the pipe to start the creation of a hollow cylinder. The glassblower would enlarge the cylinder, sometimes with the assistance of a wooden mold. Periodically the glassblower would reheat the cylinder to keep it elastic. The reheating was done at a section of the furnace called the glory hole, which was a small hole in the side of the furnace that was often at right angles to the main gathering hole. A typical cylinder was up to long. The cylinder was cooled and then cut at both ends (the "caps") by a craftsman called a cutter. The cylinder, now a tube, was then cut lengthwise to prepare it for flattening.
Glass products must be cooled gradually (annealed), or else they can become brittle and possibly break. A long conveyor oven used for annealing is called a lehr. In the case of window glass, a combination flattening oven and lehr could be used. The glass tube was placed in the oven with the slit side up. Workers known as flatteners make sure the reheated cylinder unfolds into a flat sheet. After the flat glass has moved from the hot end of the oven to the cool end, which can take hours, it is inspected, cut to the desired size, and packed. The size of each piece of window glass varied, but was limited by the size of the cylinder. Statistics for unpolished window glass imported into the United States in 1880 show that about half of the tonnage consisted of glass above by in size and below by .
Most glass factories had a summer stop where the production was shut down for about six weeks. This was done because the summer heat combined with the heat of the furnace to make the work environment almost unbearable for workers in the hot end (near molten glass). The summer stop also allowed time to perform maintenance on the facility without disrupting the production process. Window glass workers spent more time adjacent to furnaces and ovens because they reheated their product, so some companies had summer stops that lasted from the beginning of May until the end of August.