I want to make a hemispherical sundial (Baktria related!)

[Teleklos Archelaou]

Ok, this is sort of off-topic, but I'll relate it somehow! I have recently been looking at photos of hemispherical or hemicycle sundials and I'm wanting to make one. They are the most common type of sundial at the time of EB actually, and one of the best examples that survives is actually from a Baktrian city (Ai Khanoum):
https://upload.wikimedia.org/wikipedia/commons/a/ab/SunDialAiKhanoum.jpg

They are portions of a hemisphere, set into stone, with a metal bar poking out towards celestial north. Out of the lines on them, they are divided into 12 hours of the day - and the metal pointer's shadow passes along the topmost and shortest line (and therefore the shortest hours) at the winter solstice, the halfway line at the equinoxes, and the bottommost and longest line at the summer solstice. Here is another great one:

http://static.howstuffworks.com/gif/ancient-civilizations-use-sundials-3.jpg

One from Herculaneum:
http://www.home.uni-osnabrueck.de/ahaenel/sonnuhr/herculaneum.jpg

And Stabiae:
http://www.home.uni-osnabrueck.de/ahaenel/sonnuhr/stabiae.jpg

A great one from Leicester survives with good info on it here:
http://www.sundials.co.uk/~leicester.htm

So what I'm wondering is what is the best way to make one of these, assuming that I'm not a stonemason and don't have access to crazy complicated equipment? Is something like quikkrete the answer? Moulding the wet cement into something of a hemisphere? If I wanted something cheap and easy I could do plaster or something, but the vernal equinox is about ten days away so I'm thinking it'd be good to give it a try by then. Any directions or suggestions or sites or something that could help me in my quest? If you don't know anything about them, take this opportunity to learn! Given that they were so popular during our mod's timeframe, you'll learn something regardless!

[Antinous]

I know this is off topic, but did you start your project in your class?

[Teleklos Archelaou]

Not yet - we're in comedy right now. That will be at the end of the semester (April basically). I did try to set up one cpu with RTW BI today and got some stupid administrator permission error once it was installed and I tried to run it - gotta talk to the IT guys now - blech.

[chairman]

I know this is a rather tacky solution, but maybe you could try a papier-mache version (at least for a test trial or other such prototype). Otherwise, I'm not very knowledgeable about concrete or stone-masonry related construction issues. I hope someone else here is of more help.

If you make progress, please let us know and post pics of it. Good luck.:2thumbsup:

Chairman

[Teleklos Archelaou]

I'm starting to think one of those playground bouncy plastic balls (inflatable, smooth outside, fairly tough) pressed into some quickcrete might work for the basic part (deflate it when the quickcrete has set and hopefully it'd come loose from the cement as smooth as the ball is). I'd like to put it outside at times - so although I thought about a papier-mache version I'd really rather go for something more lasting even with a first try. If it works, even if it takes 6 months to get the equinox and two solstice tracks labelled properly, it'd be pretty kick-ass in the end, and if it isn't too difficult I could post images and directions on how others could manage it.

[fatsweets]

Are you pursuing a cheap way to do this or are you willing to spend a few hundred dollars? Do you have any experience in construction or fabrication? If you want to spend some money on it you could purchase an acrylic hemisphere($55) 12" in diameter, 1/8" thick wall, cut to the correct size using a hacksaw, make sure you cut as straight as possible. Then, if you have access to a Jigsaw and know how to use it you could cut out the Main body section using 3/8" Plywood, MDF or Acrylic. If this is the way you would like to pursue let me know and I can help you from beginning to end, there is a few different ways you could approach this, just need to know how easy you want to make it and what your budget is.

[Teleklos Archelaou]

As a financially challenged, single, classics teacher (who tends to spend what money he has on impressing females, buying books, and alcohol), I'm definitely looking for the budget way through this :grin:. An additional benefit from doing it this way also is that if it works I could replicate it in the future for school projects. I don't have a lot of experience in construction or fabrication but I grew up on a farm and am moderately handy with tools. Thanks for any advice you can muster though!

[Ibrahim]

As a financially challenged, single, classics teacher (who tends to spend what money he has on impressing females, buying books, and alcohol), I'm definitely looking for the budget way through this :grin:. An additional benefit from doing it this way also is that if it works I could replicate it in the future for school projects. I don't have a lot of experience in construction or fabrication but I grew up on a farm and am moderately handy with tools. Thanks for any advice you can muster though!

cut the alcohol, and wait on the women:clown:

now you have more money.:yes:

[Maion Maroneios]

Why do you actually want to make something like that? Or is it maybe another way of yours of impressing the ladies? :eyebrows:

Maion

[satalexton]

it might, nowadays geeks are the new fad for women =P and if u want proof, do as thus:
1 go to a bar that's known for it's female population.
2 drink a dozen pints
3 scream 'ALL HAIL MAKEDONIA!!!'
4 just when everybody's got the wtf look at you, start ranting publicly about all the wonders of EB (minus the romans)
5 profit.

[Maion Maroneios]

it might, nowadays geeks are the new fad for women =P and if u want proof, do as thus:
1 go to a bar that's known for it's female population.
2 drink a dozen pints
3 scream 'ALL HAIL MAKEDONIA!!!'
4 just when everybody's got the wtf look at you, start ranting publicly about all the wonders of EB (minus the romans)
5 profit.
6. Get locked up in a psychiatrical institute.

Maion

[V.T. Marvin]

Good luck with your project!:2thumbsup: Casting concrete using an inflatable ball to mould the semicircular cavity would probably be the easiest solution. The result might be too heavy however.
For a more lightweight solution you could try to sculpture Autoclaved Aerated concrete (or otherwise known as Autoclave Cellular Concrete, or under market brands YTONG, HEBEL, etc). It is extremely easy to work with. I have been once able, without any previous experience at all, to cut several actual statues and metopes with a simple hammer and chisel... :2cents: