Pennvernon Process

  • Glass and Glass Making at Ariel-Foundation Park

    Glass is made from three simple ingredients: sand, soda ash, and limestone. If sand is heated to its melting point, its properties change and create glass. By adding soda ash, the melting point is slightly lower, which makes the process more cost-efficient. Finally, limestone is added to make the material more stable—without the addition of limestone, the glass material would dissolve in water. Glass is a particularly interesting material because it is difficult to classify as a solid, liquid, or gas. Molecularly, it is closer to a liquid but appears solid. For this reason, it is sometimes called a frozen liquid.   

  • Glassmaking Innovations

    Glassmaking has a rich history that dates back to roughly 3500 BCE in Mesopotamia. Glassmaking is seen in many different cultures across the globe throughout time, and as you can imagine, we do not use the same process the ancient Mesopotamians used over 5,000 years ago. Innovations in the glassmaking process have been made all over the globe, from Egypt to Mount Vernon, Ohio. The process that changed glassmaking drastically was invented in 1925 here and was thus named the Pennvernon process.

  • The Coxey Building and Glassmaking in Mount Vernon

    When Jacob Coxey came to Ohio to build a steel casting plant, he “hit Mount Vernon with the effect of a small bomb,” according to the Mount Vernon News. Made with steel trusses shipped from the Chicago World's Fair of 1893 on circus cars, the Coxey Building measured an immense 175 ft. by 510 ft. Great enthusiasm erupted from the business community at the time, with improved value of real estate beckoning. Unfortunately, obstacles to progress and profit quickly surfaced. Construction was often halted due to digging and hitting water. For structural reasons, the building was covered in brick, with the innovative use of cement as mortar. However, once running, the steel plant consistently produced sub-quality steel. The Coxey steel plant failed and brought businesses down with it in 1902.

    Due to its proximity to natural gas reserves and sand quarries, Leopold Mambourg and James A. Chambers transformed the building into a glass factory. Though its construction cost $300,000, the Coxey Building was sold for $60,717 and renamed Mambourg Window Glass Company. Raising the standard for glass production, the company eventually invented the Pennvernon process, named after its ties to the Pittsburgh Plate Glass Company and creation in Mount Vernon. In 1906, Chambers took ownership of the company and renamed it Chambers Window Glass Company, only to have PPG take over two years later. After almost 70 years of creating state-of-the-art glass, the company closed in 1976.

    “Panic of 1893” at Ohio History Central:

    coxey building 1

    Photo: The Coxey Building once housed a glass manufacturing plant, one of Mount Vernon’s largest employers in the early twentieth century. Courtesy Kenyon College.

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    Photo: The Coxey Building ruins in Ariel-Foundation Park today.
    Courtesy Ariel-Foundation Park.
  • The Coxey Building Ruins

    The Coxey Building Ruins, one of the centerpieces of Ariel-Foundation Park, were originally built to be a steel-casting plant. The building’s namesake, Jacob Coxey, made waves when he built the huge factory complex in the early 1900s, but it never became the booming steel plant he envisioned. Instead, after Coxey’s brief and failed attempt at steel casting, the building became the home of the Mount Vernon branch of the Pittsburgh Plate Glass Company. At its peak, the PPG factory was one of the area’s major employers, with entire families, including many Belgian immigrants, working to shape and cut glass together.

    Proximity to readily available natural gas and fine sand made the factory the perfect place for glassmaking, and it was here that a new process of glassmaking, called the Pennvernon process, was invented. This process, in which glassmakers pulled ribbons of molten glass through rollers up to three stories high, dominated glassmaking globally from its invention in 1925 until the 1970s. In the 1950s, a new and more efficient process of glassmaking, called “Float Glass,” was invented and eventually replaced the Pennvernon process as the dominant way of making glass. Unable to adapt to this new glassmaking process, the factory was forced to close in 1976. What remains of the 89,250-square foot building today are a few crumbling walls and three elevator shafts, but the legacy of the industry it represents is alive and well in Ariel-Foundation Park.