Batch, Blow, and Boys: The Glass Industry in the United States, 1820s-1900



Employees at the Libbey Glass Factory in Toledo, Ohio in 1890At the end of the nineteenth century, practically all bottles were still made by skilled hand blowers using a system which had not varied dramatically since glass was first produced.  Mechanization had not affected the glass industry as it had in most other areas of production in the United States, not so much from reluctance to change but because of the complexities of making glass.  Skilled glass blowers understood such characteristics as density, surface tension, and viscosity, and could control changes in the molten glass more easily than a machine. 

Quite simply, glass is produced when pure sand (silica) is heated to a temperature of 3100 Fahrenheit or higher.  Reaching this high of a temperature in a factory was neither economical nor safe, so other materials were added to assist in the melting process.  Soda ash (sodium carbonate) and lime or limestone (calcite or dolomite) allowed the sand to melt at lower temperatures and the glass to be more resistant to water.  Furnaces, called tanks, melted the batch of ingredients. Side holes in the tanks, known as glory holes, allowed the glass blower access to the molten glass. 

Glass blowers removed a gob of molten glass at the end of a hollow iron blow pipe.  Blowing through the pipe, the blower expanded the glass and changed its shape by holding the pipe upright or swinging it.  The blow pipe was replaced by a solid iron rod, known as a pontil, and using wooden tools, the finisher worked the glass into its final shape. After cooling slowly in a kiln or annealing oven, a designer traced a pattern which then was cut and polished. This process was simplified by the 1820s, and perfected by the New England Glass Company, with the use of molds into which the glass was pressed.  Most of the glassware produced fell into two categories: flint or leaded glass used to produce finer glass products; and common or green glass used for household bottles and various containers.

Flat glass was produced using two techniques.  For window glass, the blower formed the glass into a large cylinder, then cracked it in one straight verticalGlass workers making light bulb by hand line before it was fully cooled and rolled it out into a flat sheet. For plate glass the liquefied glass was poured into a quite large shallow, flat mold, spread evenly, and allowed to cool. 

The manufacture of bottles and jars during the nineteenth century used the method of mold blowing carried out by shops consisting usually of five to seven people.  Each shop employed two to three skilled blowers and finishers and three to four young boys who opened molds and carried the product from blower to finisher to cooling oven. The blower used much the same methods in creating cut glass pieces, but inserted the glass into a hand-operated mold and once closed, blew into the mold to create the final shape of the bottle.

 Although the glass industry remained fairly unaffected by mechanization during this time period, one significant development was the organization of the workers occurring during the latter half of the nineteenth century.  Between 1877 and 1878, Local Assembly 300, Knights of Labor, was organized by window (flat) glass gatherers in Pittsburgh.  By 1880, it merged with blowers, cutters and flatteners and became known as L.A. 300 Window Glass Workers of America. The formation of this national union signaled the beginning of a rigid, detailed, and all-inclusive system of regulation of window-glass production that lasted into the early years of the twentieth century.  L.A. 300 established production limits, restrictions and regulations of apprenticeships, and controls over wages.  At the same time, the manufacturers of window glass also organized, forming the American Window Glass Manufacturers Association.  Working with L.A. 300, the two groups kept industrial strife to a minimum despite fluctuations in the market.  In similar fashion, the bottle and jar skilled laborers were under the jurisdiction of two unions depending on the type of glass used the Green (common) Glass Bottle Blowers Association formed in 1890 as a merger of several unions; and the American Flint Glass Workers Union of North America organized in 1878, which joined the American Federation of Labor in 1889.  

The only unprotected workers in the glass industry were the young boys, sometimes referred to as "blowers dogs."  Union restrictions on the number of apprenticeships (most often reserved for relatives of the skilled workers) resulted in few if any of these boys moving into more skilled positions.  By the end of the nineteenth century, child-labor laws enacted in several states prohibited the employment of children less than fourteen years of age.  The glass industry, however, was notorious for needing and using under-aged boys.  Boys as young as eight were taken from orphan asylums and poorhouses by both men and women who claimed they were guardians, providing affidavits as to the boys being fourteen or older.  These guardians lived on the wages of the children. Work was difficult and hard in the glass factories for these young boys.  The earnings of the blowers depended upon the speed of the boys who fetched and carried for them, no restrictions existed on night work, and the sharp contrast between the heat of the ovens and the cold of winter nights resulted in many boys dying from pneumonia or other diseases.

 The glass industry, however, was on the verge of major change:  a technological improvement developed by the partnership of Edward Drummond Libbey and Michael J. Owens in Toledo, Ohio.


At the Ward M. Canaday Center for Special Collections


Ballou's Pictoral Drawing Room Companion, c.1885. O-I, MSS-200.

The method of glass blowing changed little during most of the nineteenth century.  Mixing the batch and adding it to the melting pots in the furnace, blowing, cutting and finishing the glass products are depicted in an article about the New England Glass Company.


Batch recipe book of D. J. Crowley, ca. 1890s.  O-I, MSS-200.

            Crowley worked at the Libbey Glass Factory as a gaffer or foreman and finisher.  Batch recipe books were carefully and many times secretly kept by experienced glass workers. Chemicals added to the main ingredients of sand, soda ash, and limestone neutralized impurities and produced various colors of glass.  Crowley lists the ingredients for the making of different colored glass and notes changes made in amounts and quality of glass produced as well as the cost of the batch. 


Photograph, building a pot furnace, ca. 1890.  O-I, MSS-200.

            The tank or furnace was comprised of a special type of brick known as tank brick which was about 12 inches thick.  The top of the tank was usually covered by a crown made of a silica brick capable of supporting substantial loads up to a very high temperature.  Depending on the size of the factory, a tank held from 30 to 100 tons of glass which represented roughly two to three times as much glass as could be pulled from it every 24 hours.  


Blow pipe and pontil.  O-I, MSS-200.

            The skilled blower gathered glass on his five-foot long blow pipe from the tank through a hole in the side known as the "glory hole."  He then blew a bubble of molten glass and shaped the bubble by rotating and swinging the blow pipe. His assistant or apprentice gathered a small amount of molten glass on the end of a pontil and applied it to the blown glass to remove it from the blow pipe.  Then either the apprentice or another skilled worker using wood or iron hand tools shaped the glass.  The glass piece then slowly cooled in a kiln which usually took days.  By the 1880s, lehrs or annealing ovens began to be used.  In the lehr, the glass was mechanically taken slowly through a tunnel-like annealing furnace which resulted in a much faster cooling period. 


Photographs, manual glass blowing, ca. 1910s.  O-I, MSS-200.

            A glass blower (standing) is hand-blowing a 500-watt light bulb at the Libbey Factory A.  The shop approach to glass-blowing is illustrated at the Pacific Coast Glass Company's container blowing factory in San Francisco. 


Photographs of glass workers, ca. 1870s-1890s. L-O-F, MSS-066; and O-I, MSS-200Images of traditional glassworking

            Skilled workers and children were used in the glass industry, and although they worked together in shops, the separation between the skilled blowers and finishers, the batch mixers and furnace tenders, the apprentices, and the boys, was rigid.  Each shop, depending on the size, included a gaffer or foreman, and one or more gatherers, blowers, servitors or helpers, carry-in and carry-out boys, and mold tenders. The factory also included batch mixers, furnace tenders, lehr tenders, box-makers, and packers.   Factories even employed young girls to weave covers for hand blown bottles. 


American Flint Glass Workers, Labor Day parade, 1912.  O-I, MSS-200.

            In 1866, Local Union 1 of the Flint Glass Workers was chartered in Allegheny County, Pennsylvania, as a craft union and affiliated with the Knights of Labor.  The American Flint Glass Workers officially organized on July 1, 1878, as a national organization.  In 1889, the union affiliated with the American Federation of Labor.  The AFGWU negotiated major contracts covering the entire hand production division of the glass industry as well as the large automatic machine plants.  In 1904, the AFGWU moved its headquarters to Toledo.  Organized labor's presence was most visible in the community on Labor Day.  In this photograph, members of the local AFGWU union have their picture taken in front of the old YWCA before or after participating in the Labor Day parade.  Note the number of glass canes held by many in this photograph.

Last Updated: 6/27/22