Friday, March 26, 2010

A burl in the hand is worth two in the bush

Skiing down the West trail, I spotted a burl on a dead spruce tree. I have been looking for burls since forever, so this is treasure indeed. I am not quite sure why burls form; have to do some research. It appears to be a constriction in the growth process. Anyway, I marked the spot (in the woods, all spots look the same. This is why people get lost) and next day stuffed a saw in a backpack, went in and cut the burl from the tree, which, rest assured, was deader than the proverbial doornail. I then stuffed it in the backpack and skied home, where it now resides:

It is about 25cm across; not big as burls go. Many people use them as is for decorative outdoor posts. I don't know what to do with Burly above. Some poeple make bowls out of them. But I cannot decide. I am keeping a lookout for another, of course. There is real treasure in these boreal woods, if you can only get in there! In the summer, there is brush, more brush and perhaps bears lurking. In winter you can ski in the woods. The brush is buried, the bears are asleep, and there are no bugs.

It is hard to saw when you are on skis, by the way. There is nothing level, so you tend to drift away from the cut. You can't stand the way you want because 180 cm of ski is in the way. If you get off the skis, you go through half a meter of snow. Snowshoes are better for cutting, but my burl was about 4 Km from the house and snowshoes are clumsy and tiring.

Friday, March 19, 2010

A sundial at work

I'm still in sundial mode. I recently completed an adjustable equatorial. Now that we are approaching the vernal equinox, the sun actually stays up for a reasonable time; it comes through my south-facing kitchen window at about 12 noon on that monstrous contrivance called "Daylight Savings Time," which saves no daylight, much less energy. However everyone is convinced that it does (save energy). They must have been watching TV. I have no TV, thus allowing me to make more sundials. Pardon the rant. Anyway, here is the equatorial sundial doing its thing:
The sundial is set -- as best I can by protractor -- to my latitude, 61deg 47m. Or sixty-two deg. give or take. The post in the center is called a stylus; or style; sometimes a gnomon. It is also the polar axis -- which is parallel to the earth's axis of rotation -- and the shadow gives the solar time. [I am actually lying over the polar axis bit. This is a sundial, not a telescope. But I don't want to complicate matters just now.] Not the zone time; although I suppose you could rotate the dial to give you AKST or whatever. I like equatorials because the marking-out is trivial: 15 deg for each hour. With my newly made burin, I actually did the obligatory Latin motto on this sundial: tempus fugit, or "time flies."

It is hard for us moderns to believe, but in the pre-industrial revolution world, watches were for the very, very, rich. Poorer folk used pocket sundials to tell time. Some even came with a built-in magnetic compass to help you find south. The stylus, however, must point to true south, not mag south. In Willow the magnetic compass points 20 deg and a bit east of true north, towards Hudson bay in Canada, a substantial magnetic declination, as this offset is called. Having consulted the U.S. Naval Observatory, however, I know when the sun will cross the meridian and I find true south that way. See previous sundial post.

I may add that sundials use no batteries, deplete no resources, are fun to make, and, provided that you orient them properly, actually tell time. But if it's cloudy, then you will see why watchmakers made their fortune!

Monday, March 15, 2010

Retrospective: Going to the dogs

As I write, the Iditarod dog sled race is going on. This is to Alaska what the World Cup is to football (soccer, to my american readers). The race goes from Anchorage to Nome, about 1,161 miles (1,868 Km). You can find out all kinds of things about this race by googling on "Iditarod." The leader is only about 170 miles (250-odd Km) from Nome. In the old days, it would have been a month. Now a couple weeks suffices! But I don't really want to discuss the Iditarod at length; there is lots of stuff on the web. Instead, let me relate my own experience with dog sleds.

Last year, I had a visit from a friend, who comes from the southern hemisphere, Buenos Aires by name. Now in Bs.As (as it is usually abbreviated) there is a winter, and it gets down to 0C on occasion, but by and large it remains above freezing in the winter. Quite a shock awaited her: -20C considered tropical. But my friend in Bs. As had a friend in Juneau (Brenda) , who had a friend in Willow (Kathy), who ran dogs and so we wound up visiting Kathy. As we drove up we were greeted by what seemed to be an infinite number of dogs:
The first thing you notice, indeed it is forced upon you, is the enormous dog quarters area. There are probably forty-odd dogs there. They are very friendly, and they talk to you. It would be unkind to call it "cacophonous," because, after all, they are trying to communicate! What they really would like is to go run. In the background is Tom, a Yorkshireman(!) who is in charge of the dogs -- the "handler," as he is called. He feeds them, waters them, cleans up after them, but as a consolation, often drives them as well. So we met Kathy, and the two ladies agreed that a drive would be just a thing. Fortunately there were lots of spare duds. Soon our Argentina was outfitted fit to kill:
Dog driving (at -25C) is a serious business. You should have padded bibs, a parka, several pairs of wool socks, and insulated boots. Somehow the dogs manage without these things, but we did put booties on them that day.

I had brought my skis, thinking I would go skiing while the ladies drove, but a better idea emerged: two sleds would be hitched, one for the ladies and one for the gents. With Tom as my mentor I would ride along on sled 2. There were enough dogs to make up two sleds, say 16 dogs per sled. So off we went:
Notice that it's clouding up. As it does, the temperature will rise -- I predicted -10C as final temperature; I was dead on! Experience helps. Anyway, notice the Alaska trace (or hitch). There is one long trace, and the dogs are hitched to that. This is very efficient. The Greenland Inuit hitch dogs fan-wise; with all due respect, this is not the best hitch.

At first I rode seated in the sled. But after a while I got to share the "running board" on the sled with Tom. I learned a lot from Tom. Sleds have a brake -- a flat plate you step on. This, obviously, slows the sled by dragging. There is also a great big hook. This is the anchor. When you stop, you do not want the dogs deciding to go somewhere, urgently. You set the anchor. The sled must be leaned in turns. You do this by putting body weight outboard.

Eventually (oh joy) Kathy let me drive! I inherited the dogs in a "parked" state. anchor set, dogs resting.

The dogs are controlled by voice command. You say "let's go" amd faster than the speed of light, you are off! Remember to lean on the turns. If there is a fork in the trail, say "gee" to go right, and "haw" to go left. Don't have to shout; dogs hear very well and these dogs are trained to a hair. Want to stop? Say "whoa." Just like a mule team in the old days. In action, it looks like this:
Or from the driver's point of view, like this:
In the middle of all this, my cell phone rang. My daughter, with an important message. It is the most incongrous thing. Here you are, in the middle of the howling wilderness, and (a) your cell phone rings (b) it is a message relating to some other world, Mars perhaps? My reaction was "what's that noise?" Oh, the cell phone. What's a cell phone doing out here? What's a cell phone? A loud amoeba?

A great day, not given to everyone.

Meanwhile, just to end on an Iditarod note, here is a team from last year's Iditarod, about 2Km away from home:
They have a whole lot more dogs! This is serious stuff, after all. And we all gather around to watch:
Barbecues, beer, and dogs. What could be more Alaska?

Friday, March 12, 2010

The sundial strikes again

Once you start making sundials, it seems hard to stop. I have made over a dozen now. Unfortunately, I made a mistake programming up the formulas for the angles, taken from Meeus's book. I went to make a vertical sundial and discovered my mistake. The markings are a function of your latitude, the hour angle (angle made between the sun's meridian and yours) and the declination (or, for our purposes, latitude) of the sun. I put the sun on the equator. There are adjustable sundials, but they are complex.

Here's this week's crop of sundials:

The sundial on the right is a vertical sundial. The one closest to you in the picture is a horizontal sundial, the most common kind. The other two are equatorials, one fixed, the other in a trunnion mount, so it can actually be adjusted for latitude. In order to cut the markings on these, I made a burin, an engraver's tool, out of a broken drill bit. It has made the marking process much simpler. Much better than my bicycle-spoke burin. That is because it does not flex. Burins are relatively cheap on the internet, but why buy anything you can make?

The equatorials all have to point south - true south, not magnetic. Sure enough, I set my sundials with a compass and applied the magnetic declination the wrong way (blush), I am not the only navigator ever to do that, however.

There is a sure-fire way to find true south. If you go to the U.S. Naval Observatory, and click on "One day's ..." you will find a form that allows you to get sunrise, sunset, and transit times for the sun, at your location. The transit time is when the sun is on your meridian; so wait for that time, and then turn the sundial till the shadow falls on the "12" mark. It's aligned.

Sundials are fascinating. I have deviated from my original intention of building a sun compass; but this is all good practice. Now that I have my new burin, I can even carve latin mottoes on my sundials: carpe diem, nihil novum sub sole, tempus fugit, and the rest!

Sunday, March 7, 2010

Placemat in place

We left our Navajo placemat almost at the top. A demonic session a while back finished it. As I have said, the last few centimeters are torture. You can't make a shed, so it is blunt needle time. You go thread by thread with the needle. But it is done. And here she is:
I am really pleased with the result. I have finally got the hang of dovetails, if not mastered them; my "lazy lines" where diagonal colors join are OK, and the rug is really solid. So let's take it off the loom, knot up the four corners (traditional finish) and see what we have:
The placemat is finished. It will probably become a hanging in an honored place; I can't stand the thought of getting spaghetti sauce all over it, although it is washable. Its successor is on the loom as we speak. In this one I will attempt diagonal stripes. Stay tuned.