clocks and calendars
I'm reading a story about some folks throw back in the distant past. They are talking about how to determine the season and set up a calendar. They aren't doing too bad, but they obviously don't know a couple of important tricks.
Ok, for time of day, set up a crude sundial to start. Just a flat piece of cleared ground with a tall stick or pole in the middle.
Have someone keep an eye on it and set small stones at the end of the shadow every so often, or poke twigs in the ground.
After a few days you'll have the longest shadow pinned down, and that's noon. If you still have working watches or clocks, you can use those to lay out markers for the hours. Just remember that you'll have to shift them every week or two.
For setting up a calendar, you need a hunk of flat ground with a good view of the horizon (east or west) so you can observe surise or sunset.
It works best if the horizon is flat, but you can still work with it even if its hilly.
Set up a pole just tall enough that you can sight over the top. Use a rope or cord to darw a circular arc around it in the direction of sunrise or sunset.
Each day at sunrise, have one person at the sighting stick and another with a tall pole standing on the arc. Use hand signals to move them right or left until the pole lines up with the rising/setting sun. Place a marker on the arc at that point.
Over the course of the year, the markers will shift to one side until they hit a max and start moving back. Those two ends of the arc mark the solstices. The point in the middle of the arc marks the equinoxes.
Most ultures also noted the points halfway in between the solstices and the equinoxes. Those are the cross-quarter days.
All 8 points (remember the ends only get hit once a year while the other six get hit twice a year) are festivals. Because they are important seasonal markers if you are outside the tropics.
You've got about 45 days between each, which is good enough for a crude calendar.
If you've got more gear you can do better on the sundial. Use a rod pointing at the Celestial pole, and a couple of half-circle bands to support it. The hour marks on the band at right angles to the rod will be evenly spaced and not need to be changed over the course of the year.
This entry was originally posted at https://kengr.dreamwidth.org/1152881.html. Please comment there using OpenID.
Ok, for time of day, set up a crude sundial to start. Just a flat piece of cleared ground with a tall stick or pole in the middle.
Have someone keep an eye on it and set small stones at the end of the shadow every so often, or poke twigs in the ground.
After a few days you'll have the longest shadow pinned down, and that's noon. If you still have working watches or clocks, you can use those to lay out markers for the hours. Just remember that you'll have to shift them every week or two.
For setting up a calendar, you need a hunk of flat ground with a good view of the horizon (east or west) so you can observe surise or sunset.
It works best if the horizon is flat, but you can still work with it even if its hilly.
Set up a pole just tall enough that you can sight over the top. Use a rope or cord to darw a circular arc around it in the direction of sunrise or sunset.
Each day at sunrise, have one person at the sighting stick and another with a tall pole standing on the arc. Use hand signals to move them right or left until the pole lines up with the rising/setting sun. Place a marker on the arc at that point.
Over the course of the year, the markers will shift to one side until they hit a max and start moving back. Those two ends of the arc mark the solstices. The point in the middle of the arc marks the equinoxes.
Most ultures also noted the points halfway in between the solstices and the equinoxes. Those are the cross-quarter days.
All 8 points (remember the ends only get hit once a year while the other six get hit twice a year) are festivals. Because they are important seasonal markers if you are outside the tropics.
You've got about 45 days between each, which is good enough for a crude calendar.
If you've got more gear you can do better on the sundial. Use a rod pointing at the Celestial pole, and a couple of half-circle bands to support it. The hour marks on the band at right angles to the rod will be evenly spaced and not need to be changed over the course of the year.
This entry was originally posted at https://kengr.dreamwidth.org/1152881.html. Please comment there using OpenID.