On my desk I keep a couple of notepads in which I’ll jot down ideas or interesting things I’ve seen. Sometimes I’ll write down notes on books I’m reading. These writings may languish for a considerable time before I return to them. Sometimes I’ll find that what I thought was relevant or interesting at the time is no longer, but more often I’ll make new connections, and so discover novel lines of inquiry.
From the last month or so:
On 19 September I was waiting at a traffic light facing West. It was dusk, and the orange band of twilight reached from the treeline in the middle distance to about 20° above the horizon. A light caught my eye, and I saw a bright fireball slightly South of West just inside the twilight band of orange. When it’s apparent motion had taken it about halfway to the treeline, it split into two parts, each traveling on a path 45° from the original trajectory. Just above the treeline, the parts showered downward, sort of like an inverted firework. An amazing sight, and well worth waiting at a stoplight.
On 12 October I passed a member of the local constabulary stopped on a freeway overpass operating what looked like a video camera pointed at the westbound traffic. I was tempted to ask what he was doing, but given the militarized state of police in this country, not overly so. I speculated: was he videotaping traffic, checking speeds, what?
I was going to the company storage facility, and had a clear view of the overpass and freeway. A few minutes later, I saw a car get pulled over in the westbound lanes. So. One officer is checking traffic speed, and when someone is driving a bit too fast, he radios another officer to pull them over.
Same day, same location, same time. I noticed a couple of hawks circling overhead, one apparently chasing the other. I’m no ornithologist, but my experience with hawks is that they’re solitary birds, riding thermals looking for prey. The hawk chasing would emit a scream every so often, while the other bird looked like it was trying to get away. A turf war!
After a few minutes of chasing, both birds dove behind the trees, only to shoot right back up. I considered that this might be a mating ritual, but given the time of year, that seemed unlikely.
18th Century Solar Still
I re-read Patrick O’Brian’s Aubrey-Maturin series of naval adventure/historical novels this summer. On long voyages or while trapped in the Doldrums, fresh water could become a real concern. This got me to wondering why no one invented a maritime solar still to produce fresh water.
The technology certainly existed. Condensation was well-understood, as evidenced by the copious amounts of distilled spirits available. So I’ve been noodling around with the challenge of how an 18th century sailing ship could produce fresh water.
There are constraints, none particularly onerous:
- Only materials and tech from the late 18th century can be used.
- No glass or mirrors, as these materials tend not to do well in an 18th century maritime environment.
- Operable by officers or petty officers of the time.
- The device can’t be so cumbersome that it can’t be stricken below decks on short notice.
- The device must be maintainable by the ship’s crew while at sea.
- The device must produce a reasonable amount of fresh water. Not necessarily enough to supply the entire crew daily, but enough to ward off dying of thirst.
My experience with solar stills comes from Boy Scout training where you dig a hole, spread a garbage bag or other plastic across the hole, weight the center with a rock, and let evaporation do it’s thing. Yes, you are gong to want a container at the bottom of the hole located at the apex of the inverted cone to catch the moisture. You don’t get a lot, but it will keep you alive.
Research into modern maritime solar stills reveals that the most common design is an inflatable device where seawater is poured into a circular channel and a Hershey Kiss type of clear cover evaporates the water. The condensate collects in the center of the device, where a tube is supplied to suck the water out. Stated production rate is 500 ml/day.
My idea for an 18th century still is to have a vessel (probably copper) surrounded by a petal arrangement of polished metal on hinged leaves in a circular arrangement so that the focus can be adjusted according to latitude. I figure that a worm gear and band (hose clamp) type of arrangement will allow for adjustment of the ‘leaves’, while the vessel can be adjusted vertically to account for the change in focus as the leaves are manipulated.
As the water in the vessel is evaporated, it travels through a ‘worm’ (coiled copper condensate line) to a waiting barrel. Viola! Fresh water. I’d expect that salt would be a byproduct; itself a valuable commodity in the 18th century.
I’ve gotten as far as making sketches of the gross structure as well as the parts and checked the prices for materials. A fun little project.
The Dear Surprise
Speaking of Patrick O’ Brian’s novels, I re-read them this Summer. This time through, I bought a couple of companion books: A Sea of Words (Dean King, Henry Holt & Company, 1995) and Harbors and High Seas (Dean King/John B. Hattendorf, Henry Holt & Company, 1996).
A Sea of Words is a lexicon for the novels that explains the more esoteric naval terms, as well as people, places and things that the reader encounters in the series. If you don’t know a dumb chalder from a mainmast truck, this is the book.
Harbors and High Seas provides a synopsis (without giving the book away) of each novel along with providing facts and tidbits of the people and places encountered. Unfortunately, the edition I bought doesn’t include the last two novels, The Hundred Days and Blue at the Mizzen. I expect revised editions remedy this.
And So . . .
The universe is an endlessly interesting and varied place. Hardly a day goes by when I don’t find something of note. The world may be going to Hell in a hand basket, but I’m going to have some fun on the way.
Oh, By the Way
This is the 500th published post on this blog. I’ve actually written 502, but there were . . . issues with two posts. Thanks for reading.