After kicking around (and kicking to death) the early airship idea (https://www.alternatehistory.com/discussion/showthread.php?t=257395) I’m wondering if paper is a near necessity for an original invention of a hot air balloon. One story is that the Montgolfier brothers got the idea from tossing a paper bag in the fire place that promptly caught an up draft and shot up the chimney. Another story is that while watching laundry drying over a fire the hot air would get trapped momentarily lifting the cloth, giving them the idea. Both of these are prosaic enough to give one the idea but I’m wondering if the crux is testing the idea. I’m thinking there is a size so small cloth is too heavy in earlier times. Consider the Kongming lanterns are paper, Gusmao’s balloon was paper, the Montgolfier brothers were paper manufactures with some of their early balloons containing paper. In theory if you were wealthy enough and the idea jumped out of your head like Athena fully armored you could just say “Get me 600 lbs of cloth!” but I just don’t see getting it right the first time and then you’d be back to “Get me another 600lbs of cloth!”.
Is paper necessary to invent the hot air balloon?
- Thread starter Unalist
- Start date
Why not silk? Yes, I know that OTL silk (that had been rubberized) was apparently used for hydrogen balloons in the late 18th Cent.
Silk might work
But I still wonder if there is a min size for small scale, that below which, the silk would be too heavy. I'd need to get into the math of how much hot air of what temperate creates how much lift versus the material to be lifted. One other thing I see at least slowing things down is that without rubberizing silk is porus and you'd need to allow a fire (smoke actually) time to clog the pores for it to become airtight. Otherwise you could get the impression that you'd never be able to get enough or hold enough hot air to make it work.
If your model paper balloon worked at least you'd have encouragement to tinker more with taffatta or silk or whatever you were trying to scale up in.
But I still wonder if there is a min size for small scale, that below which, the silk would be too heavy. I'd need to get into the math of how much hot air of what temperate creates how much lift versus the material to be lifted. One other thing I see at least slowing things down is that without rubberizing silk is porus and you'd need to allow a fire (smoke actually) time to clog the pores for it to become airtight. Otherwise you could get the impression that you'd never be able to get enough or hold enough hot air to make it work.
If your model paper balloon worked at least you'd have encouragement to tinker more with taffatta or silk or whatever you were trying to scale up in.
Inspired by Australia's skywhale, various organs could have been used to fabricate an envelope, sewn with vegetable-based thread, as hypothesized in use by ancient Incas. It's certainly a more tasteful use than haggis. A blue whale's intestines are about 500 feet in length, and the stomach is quite large as well.
Traditionally, "goldbeater's skin" (the outer membrane of a calf's intestine, so called because of it's use in the production of gold leaf) was extensively used OTL in the late 1800s and early 1900s for production of gasbags in airships.
Tallest Skil
Banned
Bingo. You don’t need paper if you can treat animal hide and get it thin and light enough.
These guys built one with cotton. They say it needed a long time to lift off because it took a while for the soot to clog up the porous fabric. But it can be done.
http://www.nott.com/Pages/projects.php
http://www.nott.com/Pages/projects.php
Untreated fabric also works if it is woven finely enough (something that ancient societies could already produce). Soot clogs the pores and the loss of lift is negligible. But paper is far better for proof-of-concept. Fabric works well enough for large balloons, but tends to be too heavy for small ones unless it's ridiculously fine.
What is the history of goldbeater’s skin? The earliest reference I have found off hand for ballooning was 1880’s. It was used earlier but for ballooning was 1880s. The references I found it was used with paper or fabric to make it air tight. The use also seem to be with hydrogen (another 17th century product) or other lighter than air gas. Could goldbeater’s skin be used alone and with hot air?
Otherwise hot air and paper ala Kongming balloons were used in the 3rd century BC China.
I'm not seeing how you could say accidentally inflate an intestine with hot air and have it float off or get the idea of ballooning and work on testing that way.
Otherwise hot air and paper ala Kongming balloons were used in the 3rd century BC China.
I'm not seeing how you could say accidentally inflate an intestine with hot air and have it float off or get the idea of ballooning and work on testing that way.
Last edited:
Goldbeater's skin is extremely fragile, so I don't think a balloon can be made of it alone. Or at least, not one that can do anything useful.