[slickr-flickr id=”12687067@N00″ type=”gallery” tag=”fernfrost”]
It’s too bad we have to worry about energy efficiency. As new windows replace old ones in our homes, fern frost is becoming a lost memory. Fern frost is the stuff that forms on glass when humid air inside meets cold air outside. The first two images in this gallery show the enchanted sapphire forest I found on my bathroom window yesterday at dawn.

We used to see it in the windows of the house where I grew up. After I left home, I forgot these fanciful visions from childhood. Many years later I moved into a flat in an older building. The place was poorly maintained, in fact it declined during the years while I lived there. It was hard to keep the place warm in winter. One benefits of living there was seeing the winter window displays.

The structure of the formation depends on dirt or other particles or imperfections on the glass. One of the windows in the apartment featured distinctive striated feathers like those in the fifth image. Sometimes it looked more like strings of pearls. The dark third image shows the same window one night, back lit by the streetlight. Another window in the same apartment usually had a pattern of jagged plates like a jigsaw puzzle (sixth image). Every window has a unique way of expressing itself. The glowing fourth picture appeared on my office window at dawn on February 20, 2008, the day my mother died. It reminds me of milkweed seeds.

Some people call these patterns frost flowers, however that term may also be applied to a different phenomenon. When the weather turns sharply cold over unfrozen ground, it may cause plant stems to squeeze out, by capillary action, layers of ice resembling leaves or petals. I have yet to observe this peculiar beauty.

I was glad to move out of the old dive, but sorry to say goodbye to those windows. My current apartment has mostly newer ones. Fern frost can form on double-paned glass when the air outside is extremely cold, but this seldom happens. This place still has two old windows in the bathroom and hall, and I was delighted to discover this glass attracts foliage patterns much like fern fronds. It’s a nice sight to discover when I crawl out of bed on a winter morning and head for the toilet.

I must pay for the show. A lot of heat must escape through these windows. Maybe I should petition the landlord to replace them, but I’d rather not.