Vol. XVIII No. 3 - FALL 2007

By: Kathyrn Gemperle

If you live in a home with window glass that seems to have a ripple in it, it’s because the glass was made before the mechanization of the process. All glass, even window glass is made by melting sand (silica) soda ash and lime in a furnace to 2400 degrees F, creating a blob of glass.

Prior to mechanization the process of making glass required craftsmanship. The melted blob of glass was then used by glass blowers to create a thinner glass by blowing through a tube. A gatherer would put the metal tube into the furnace and withdraw the blob. This hot blob was rolled on a metal surface to get rid of the bubbles. The gatherer would bring the blob to the blower who would blow air through the tube to create a bubble. That bubble could grow to a cylinder that was up to eight feet long.

The bubble was cooled just enough to become a solid then the rounded end was cut off. The rounded piece was remelted while the cylinder was cut with a drip of molten glass lengthwise and then set on a metal plate to be put back into the furnace. The cylinder would uncurl in the furnace and the flat glass was gradually cooled and stretched. It was transferred to the cutters who cut the glass in a variety of sizes and prepared it for shipping in wooden crates with straw packing.

This was a highly skilled operation that required skilled craftsmen to do the blowing. Most of America’s skilled glass blowers were from Europe and had been trained there. In the early days of the Colonies glass had been shipped from Europe. Once a glass industry began in America it centered along the east coast. The new factories had to have furnaces and a ready supply of power from coal. It helped if there was also a ready supply of sand. Besides several sites in Massachusetts, Pittsburgh, Pennsylvania had the requisite elements nearby. In 1794 two companies began production near Pittsburgh. In the next twenty years this was greatly expanded.

In the early 1800s, a process for making pressed glass was invented and more objects were made of glass. Eventually the addition of chemicals brought about colored glass and with that technology art glass and opalescent glass. Colored glass was used for windows and in pieces for stained glass. By the late 1800s, the glass industry had diversified. In Milwaukee the industry focused on bottle production which were blown and eventually pressed. The beer industry had a constant need for bottles. In Kokomo, Indiana the Opalescent Glass Works specialized in beautifully colored opalescent glass for stained glass windows. In Streator, Illinois the Streator Glass Company began in 1887 to make what was called Cathedral glass. Also in Streator was the Streator Bottle and Glass Company.

In addition to skilled craftsmen, these factories relied on the cheap labor of young boys who not only put the first pipe into the molten glass but were responsible for the carrying of finished glass to the packers. The working conditions were hot and dangerous. In the summer the whole industry shut down for two months beginning at the end of June. In the late 1880s child labor laws were enacted and compulsory school attendance became a factor in many manufacturing industries. Still, boys over the age of 14 could work in glass factories and be paid less than half of what the adults were paid.

In 1902, Irving Colburn in Toledo Ohio received a patent for a “glass working machine” that that rolled stretched and pressed glass into sheets. In 1903, John Lubber of the American Window Glass Company found a way to make a continuous 30 foot cylinder by machine. This still required flatteners to make sheets of glass. Next came the mechanization of the whole process with ladles carrying chemicals to the furnace. For the next twenty years the whole industry changed and the glass blowers and their young helpers were replaced by machines. Up until 1920, the glass was still cut by hand and packed by hand.

In 1920, Pittsburgh Plate Glass Company invented a machine that could make a continuous glass sheet of what is called float glass. This molten glass is floated on molten tin and is made continuously 24 hours a day, 365 days a year. All the people who worked in the glass industry had to become trained machine operators. Production rate moved to one million sq. feet of glass per day.

In 1903, Michael Owens invented a process for machine made bottles. Despite the ability to make pressed glass forms nearly a century before, the narrow neck of the bottle could not be achieved by machine until Owen’s invention. The early bottles cost one cent a bottle. With mechanization the cost was one cent for 15 bottles. Just as with other companies, the Owens Company united with other manufacturers. It became the Owens Brockaway Glass Inc. of Streator Illinois and then Owens-Illinois, then Libbey, Owens and Ford Glass Company.

In the 1890s, the glass industry attempted to create a monopoly. The first step was the United Glass Company of Syracuse, New York which purchased all the glass manufacturing plants in Illinois. This was in 1889. In 1893, an attempt to unite all the glass companies failed when one company, The Chambers Company would not go along with the plan. Part of the problem was the Window Glass Workers Association with 6,000 members who said they would strike if their wages were reduced. Another element was the low cost of imported glass.

Eventually, Pittsburgh Plate Glass company was able to gain control of all the plate glass mills in the country. This would effectively eliminate the “jobbers” who were the middle men in glass sales.

George F. Kimball of Chicago who had his own business as a jobber on Wabash Ave gave it up and was put in control of the Chicago territory of PPG.

The glass in Chicago, it was probably made in Streator, Rock Island and Ottawa. Some may have been made in Milwaukee and some glass may have been shipped from Pittsburgh because of the rail connections to Chicago. A jobber would handle the delivery of the glass to the window manufacturers. The windows would be brought to the construction site and installed by the carpenters. So when you look out some of your windows and they have a little ripple, think about all those people who worked to make the glass before 1902, who lost their jobs as craftsmen and became machine operators, who knew a whole lot more about the production of glass than we ever will.

Interested in learning more? I visited the Pittsburgh Plate Glass exhibit at the Pittsburgh History Center and learned how much glass making was centered in Pittsburgh and how the industry changed. On one map I noticed that Streator Illinois was mentioned. The rest of the research is from the Tribune archives and some articles found on line.