Friday, October 23, 2009

Orsoni Furnace and Acqua Alta

Today, we had to plan around a general strike of the public transportation union. This was not as difficult as it may sound. Apparently, strikes happen fairly often here and there is a certain order to it. Strikes are planned and announced in advance, and while most of the vaporetti and busses will not run throughout the day, they still run in the morning and evening so people can still get to and from work. Some vaporetti, like the one between San Zaccaria and San Servolo, run as usual so that people on outlying islands won't be stranded. So, all told, it just took a little extra walking this morning before our visit to the Orsoni furnace, the only glass making factory on Venice. There, they produce glass for mosaics, including all of the tiles with gold leaf which are used in the restoration of St. Mark's Basilica. We weren't allowed to take pictures of the furnace itself, but here are some from the rest of the tour.
This is the color library, where mosaic artists can choose the specific colors they need. They can then have the glass cut at the factory or buy it in large pieces and cut it themselves.
Here's some glass being cut.
To prepare the gold leaf, it is first put on a very thin piece of glass using steam.
Then, in the furnace room, molten glass is poured over the other side and the whole thing is flattened. The resulting glass pancake is picked up with a sort of spatula and put to the side to cool for just a few moments before it is collected and put in a container with the others.
These pieces are cut by hand, I assume with a diamond-tipped tool. After a grid has been drawn, the plate of glass is just snapped apart into separate tiles. The excess glass is tossed aside to be melted down and reused.

On the way back to our boat stop at San Zaccaria, we passed by the Piazza San Marco. It rained yesterday, and we are experiencing our first acqua alta (high water). The water hasn't been high enough yet to be much of an inconvenience- I haven't needed to buy boots- but that's still a possibility.
Periods of acqua alta occur several times a year and are caused by normal environmental factors, but the problem has been aggravated by human actions. For example, the use of underground water supplies once accelerated the sinking of Venice. The wells are no longer in use, but, more recently, global warming has caused sea levels everywhere to rise.
Acqua alta is a problem not just because it's wet and creates inconvenience; in addition to erosion from the usual beating of waves, the saltwater is caustic. We've been warned not to walk in it without boots, because it would ruin our shoes. The higher the water gets, the greater the damage is to buildings and streets. Acqua alta also threatens priceless works of art, not only in the form of architecture or outdoor mosaics and frescos, but also, for example, to works stored in the Guggenheim Museum, which sits right at the edge of the Grand Canal.

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