Thursday, 12 April 2012

Elephant No. 193: Stacked Glass Pebbles

I have hardly any time today, so I thought I'd simply try stacking glass pebbles into some kind of elephant.

The most familiar type of glass to most of us is soda-lime glass, which has been used for centuries in windows and vessels such as jars and drinking glasses. Made of 75 per cent silica, mixed with sodium oxide and calcium oxide, soda-lime glass is brittle and transparent, and accounts for about 90 per cent of all the glass made today.

Glass was first produced in Mespotamia around 3500 B.C. The term "glass" derives from the Latin word glesum, used to describe a transparent substance made during the late Roman Empire at the glassmaking centre at Trier in modern Germany.

Roman gaming die, ca. 2nd century A.D., discovered in Egypt in the 1920s.

Glass can be made with many other substances, although silica quartz remains the primary ingredient in most types of glass. One common additive is lead oxide, which is highly refractive and is used to make lead crystal. Boric oxide is also relatively common, and is used to make heat-resistant borosilicate glass for scientific and culinary applications. The glass used in fibre optics contains no silica, but is instead made of 90 per cent alumina and 10 per cent germanium oxide, resulting in an extremely clear glass suitable for communications networks.

Fibre optic glass.

Recycled glass, or "cullet", is another common ingredient in glassmaking. However, although cullet saves on raw materials and energy, the impurities it contains can cause product and equipment failure. The addition of agents such as sodium sulphate, sodium chloride and antimony oxide can help with this, reducing the number of air bubbles in the final glass mixture.

To make glass, the raw materials are mixed, then the mixture is placed in a furnace. After melting, stirring and refining to remove bubbles, the glass is formed via methods such as blowing, pressing, floating, rolling and extrusion. Once the form is produced, the glass is usually annealed—slowly cooled in a controlled manner—to remove the potential for stress fractures. Finally, surface coatings may be added to improve durability, toughen the glass, or give it optical properties. Interestingly, compact discs are actually coated with a type of glass—chalcogenide glass—which forms the rewritable surface.

Although glass is used extensively in art for everything from stained-glass windows to mosaics, I thought I'd cover those in a future post, as I'm hoping to get to some of the more traditional artistic uses of glass before this blogging year is up.

For today's elephant, I used this bag of glass pebbles from the dollar store. I think these are supposed to be something you add to the bottom of flower vases, but I bought them several months back because I liked the idea of using them as magnifiers.

I started by laying out a first layer in the shape of an elephant head. This was harder than I expected it to be, partly because the round shapes don't really allow for much definition. It was also quite hard to photograph this layer in particular.

After the first layer looked as good as I thought it was going to get, I began stacking a second layer of pebbles over gaps in the first. The pebbles have a somewhat flat bottom, which helps them to balance over gaps; unfortunately, they also have a tendency to slide around a lot. This made the activity somewhat frustrating, as when the pebbles slid, they tended to take more pebbles with them, meaning I had to rebuild a few areas several times. I even tried turning the pebbles upside-down, thinking that the roundness of the domed side would sit nicely in the gaps. It didn't. In fact, the domed side generally widened the gaps even farther. I have no idea why.

I continued with the second layer, stacking primarily over the face and trunk, with a few trailing pebbles on the ear.

To finish, the only things I added for a third layer were an eye and a tusk. It's pretty hard to see these in the photograph. I stopped there, because I didn't want to tempt fate. If I had been gluing these together, I could probably have done more, but I wanted to see what I could do with simple stacking.

This only took me about 15 or 20 minutes, and it wasn't difficult once I figured out how best to stack these. It's quite pretty in real life with light shining through the three layers, and it was interesting to see how the areas with more layers darkened.

I liked the effect enough that I wish I'd had enough time today to make something more elaborate—perhaps glued to a sheet of glass to hang in a window. Oh well, next time.

Elephant Lore of the Day
In January 2012, a female Asian elephant at Amsterdam's Artis Zoo became the first of her kind in Europe to be fitted with a contact lens. Although elephants are notoriously near-sighted, the contact lens wasn't to give her better vision, but to treat an injured eye.

A few weeks earlier, 45-year-old matriarch Win Thida got into a scrap with one of her fellow zoo elephants and suffered a scratched cornea. The eye began watering right away, and she had trouble seeing. Left untreated, the eye would likely have developed an infection and blindness might have resulted. If Win Thida were fitted with a contact lens, however, the eye would be covered, and given a chance to heal.

Veterinarian Anne-Marie Verbruggen had fitted horses with protective lenses before, but never an elephant. In order to make sure things went smoothly, she practiced the procedure with Win Thida for a number of weeks. The main difficulty was Win Thida's height. Because elephants have trouble breathing if they lie down for too long, the operation had to be done with Win Thida standing. This meant a very tall ladder, which wasn't ideal for such a delicate operation, but the best that could be done under the circumstances.

On the day of the operation, Win Thida was anaesthetized in a standing position. Since she had been training with Verbruggen, Win Thida was prepared. The procedure took less than an hour, and Win Thida was obviously happier right away.

The vet who fit Win Thida had to practice the procedure with the elephant for weeks.
Win Thida and veterinarian Anne-Marie Verbruggen during the delicate operation.
Photo: AP/Artis Zoo


  1. Well you are over half way through the year Sheila. Congratulations! I wonder if you always have a number of different ideas for future elephant likenesses (in the bank) or do you go with what moves you each day? I also wonder about the materials-are you always going down to the art shoppe/craft store or do you have some marvellous stash at your house.
    You are on day 193 and I think I would have run out of ideas about 173 days ago.

  2. Thanks, Barb! I do have a list of possible ideas on a spreadsheet, to which I add whenever I think of something. Oddly enough, I often do something not on the list when I happen across something that I think might be interesting to play with. And yep, I do have a ton of stuff at my house, left over from all kinds of other projects. Although I do like to go to Wallack's and other places to poke around!