Light 09: Lighthouses

Welcome to the 2023 Advent Calendar, which this year is just a list of things that light up all pretty. Previous entries are here. If you enjoy this and want to encourage me to bang more things out on a keyboard, consider supporting my Patreon, or sending something off of my Christmas list. If you'd rather support my spoiled pets, their Ratmas list is here. If you want to spend money but not on me, you can direct your donations to Mainely Rat Rescue, who handles rescue and foster operations for rats, mice, gerbils, guinea pigs, and other small mammals in the New England area, or the MSPCA, where my critters got their medical care before I found a good exotics vet, and where I picked up Koda and Yogi. 

Enjoy your trip through the cavalcade of things that go blinky-blink in the dark!

For thousands of years, lighthouses lit the way for mariners. They dotted the shoreline, their lamps providing a reference for navigation -- and, more critically, for the immediacy of the nearby rocks. 

Prior to electricity, keeping a giant beacon lit through the night was something of a challenge. The earliest "lighthouses" were more "a big fire on the top of the tallest local hill"; obviously, fires need tending, so someone had to stay up all night to keep it going. Building a shack around the fire -- ideally of something like stone or mud brick, which doesn't burn -- helped shield it from the wind and allowed the keeper to catch a few Zs.

Oil lamps and candles were next. The lighthouse keeper still didn't get more than the occasional nap, as self-trimming wicks weren't invented until the 19th century. Ordinary people kept a pair of tiny scissors next to their candlestick to snip the ash off the tip of the wick and keep the light burning. Lighthouse keepers needed something slightly heftier. Wick-trimming was something of an art form, as an uneven wick would sputter and spit, and produce a dimmer light. I found an instruction sheet online that specifies the wick needs trimming ever four hours, which is less unbroken sleep than I could function on. Some lighthouses had multiple keepers to rotate the task, but many did not, making the job a grueling and lonely one.

Electric lights, of course, transformed the job of the keeper into less of a constant grind and more of a "stay there in case something breaks" deal, not unlike many of the overnight shifts I worked when I was in IT. The optics involved in focusing the light into a collimated beam are fascinating -- the Fresnel lens first employed for the task is still used in theatrical lights today.

Boston Light, the oldest continually-operational lighthouse in the US, has been sadly made redundant by GPS, but you can still see it and a few others on one of the Boston Harbor Tours.