Glass has been used for almost 5000 years. Since glass is primarily made of sand it is not surprising that its first known use was in Egypt and Babylonia about 2500 BC.
Glass is not a solid in the scientific sense but a super-cooled liquid since it does not form crystals during the cooling period.
Pure silica in the form of sand melts at around 1700°C which is impractical for most uses and is therefore mixed with Sodium carbonate or Potassium Carbonate. Soda Glass is the most common since it cools slowly and can be worked easier. Too much sodium and the glass becomes soluble in water so limestone is added to counteract this problem.
Most glass tends to be green due to the impurities in the sand. The ability to produce clear glass was not discovered until about 100 A.D. Small amounts of manganese were added to offset the colouration caused iron oxide etc. and the result was a clear colourless glass which could then be used for windows and mirrors, however it took another 1500 years before glassmakers were able to make window and mirror glass similar to what we use today. Glass containing Manganese, if exposed to the sun for prolonged periods of time- 75 to 100 years, will re-oxidize and change colour varying from light aqua blue to deep purple. This phenomenon is known as sun-kissed amethyst and is often found on the old glass telephone line insulators.
The addition of lead-oxide to pure quartz sand was found to increase the brilliance of the finished product and allow deeper engraving.
Glass over the centuries has been primarily used for containers and decorative articles and these are the items of special interest to collectors.
Since the range of collectibles is huge, collectors tend to specialize in specific categories.
The Bottle collector who can tell you the history of an old town or village by the types of bottles found in the municipal dump is more of an archaeologist/historian than a collector. He or she becomes an export on style and material used in the bottles over the last 200 years. The rise and fall of products and fashions are reflected in the bottles and their labels. For example Lydia E. Pinkham in 1875 devised her “Medicine for Women’s Complaints” and the product became extremely successful. The fact that it contained 20% alcohol probably did nothing to hurt the effects of the medicine, especially during Prohibition in the 1920’s when it enjoyed its highest sales.
Until the early 1800’s all glass vessels were blown. That means that a glassblower took a blob of molten glass on the end of a hollow rod and blew a shape similar to a child blowing into bubble gum. Glass makers had long discovered the use of molds in shaping their product but for hollow ware it still needed the glassblower to blow the glass into the mold. The result was the shape of the mold was the same on the inside as it was on the outside. The invention of the mechanized press mold in the 1820’s in the States allowed items to be produced with elaborate patterns on the outside and smooth interiors. This meant that glass bowls, vases, jars and drinking glasses could be produced for far less cost and without the need of the highly skilled (expensive) glassblowers and glass cutters. Glass products were in high demand and glass factories sprung up and burned down wherever raw materials and fuel could be found. The first documented Glass Factory in Canada was at Mallorytown Ontario east of Kingston in 1839. The high point for Canadian Glass makers was the late 1800’s when Canadian Plants were producing half of the glass needs of bottles, lamps and tableware for the Canadian market.
From the Pressed Glass Collectors perspective there were four important factories producing Pressed Glass: Burlington Glass Factory, Nova Scotia Glass Company,
Jefferson Glass factory of Toronto and Hamilton Glass (which became Diamond Flint and eventually Dominion Glass). Since very little pressed glass was marked and pattern makers changed jobs quite often, it is a fascinating job to learn how to identify “Canadian Glass” from other pressed glass. Most of this glass was clear and very little of the production was coloured since it was designed for the use in homes and to imitate they more costly and fashionable crystal glassware of the upper classes.
However there are 2 main collectible categories in coloured pressed glass.
The earliest is that of Carnival Glass.
Originally known as “poor mans Tiffany” it was made starting around 1908 to compete with the iridescent Art Glass of Tiffany, Gallé and other famous and expensive glass makers. As with any product that becomes popular, it was made in large quantities and eventually became used as prizes in Carnivals, hence the name Carnival Glass. The considerable number of patterns, shapes and colours makes Carnival Glass an interesting collectible. However, beware of fakes. Before buying Carnival Glass, know your product and know your dealer. Most reproductions are easy to spot by the educated eye.
The second is that of Depression Glass. Made during the 1930’s the product was designed to sell in the Five and Dime stores and was also used extensively as give-a-way premiums. Made in pastel shades and in a variety of patterns, it again is a fun collectible. However, it was not high quality glass and therefore it scratched and chipped easily. Some patterns have been re-issued and some have been reproduced, so an educated eye and known seller are important. Both Carnival and Depression Collectors have clubs and extensive books have been written on both.
The most recent glass Canadian Glass Collectible is that of the “Cornflower pattern” Created by W. J. Hughes of Toronto around 1912, Jack hand-cut the pattern in his basement for many years, packing the finished product into his car and going on the road selling. He purchased his blanks from many different glass companies.
By the time his son-in-law Peter Kayser joined the company in the mid-40’s it had achieved a strong reputation for quality and was a staple in a great many Canadian households. From then until its closing in 1988, the company produced a diverse line of tableware in the Cornflower pattern. It is becoming very collectible, especially the uncommon coloured cornflower. As usual with glass collecting, there are copies and similar patterns on the market so the collector must do the necessary homework.