All discoveries involving fire were made in the first 10 KY !?

"Proof" that all inventions about the uses of fire were made in a very short time.

We can read surprised or admirative comments about how strange it is that primitive people could have invented so many things, so early, once they had fire : boiling without containers, charring, making tar and glue, charcoal, transforming stones by heat (for knapping...), transforming clay in hard material, fumigating of meat, fish and skins, hardening of wood points, ....

But let's do the maths...

... and it will soon be clear that even made by mere chance, all inventions about the uses of fire were probably made in a very short time.

Parameters of the hypothesis :

• 200 K people,
  from various early human species, and maybe some of them having relatively small brains and limited creativity,
• 15% of them all (30 K) having some knowledge of fire 
• ... and using fire daily during 10 KY
• 1 fire for every 5 people (families), fire burning 5 hours per 24h, each day of the year

Fire used for cooking, for heat, for protection against beasts, for technological processes, for hunting.
Some people knowing how to create fire, other knowing only how to preserve fires or coals.
People from tribes who did not use fire would not be included in the calculation.
 Results :
Total number of hours of experimentation : more than 100 billions hours
30 K / 5  * 10 K * 5  * 365 = 109 500 000 000 hours of experimentation.

This is a kind of primitive crowdsourcing, allowing for discoveries made by mere chance, during all kinds of events, in all kinds of environnements.

This is the equivalent of a continuous experiment lasting for more that 12 millions years !
30 K /5 * 10 K * 5 / 24 = 12 500 000 years.

That should be more than enough to make every possible primitive discovery about the uses of fire.

Next task : find real numbers and dates

• When did fire began to be widely used by humans and pre-humans ?
   200 KY, 400 KY, 1MY ago ?
• How many humans and pre-humans lived at that time ?
  Chimpanzees, now endangered, are still ~200,000 ;
  
  Any reason for the first humans (from all human species), opportunist omnivores, with a wider range of habitats, to have been less numerous ?

Starting a list of publications where some hints should be found...

104,000 [288,000 in 1973] Bornean Orangutans, endangered
http://www.iucnredlist.org/details/17975/0

~100,000 Giraffes in 2015
[not human-like at all : much more specialized, endangered, big and not so "sustainable" beeing]
http://www.iucnredlist.org/details/9194/0

415,000 African Elephants in 2016,
[not human-like at all : much more specialized, endangered, very big and not so "sustainable" beeing]
https://www.theguardian.com/environment/2016/sep/26/african-elephant-numbers-plummet-during-worst-decline-in-25-years

900,000 American black bears in north america only
[not exacty human-like but also "opportunist omnivores"]
http://www.iucnredlist.org/details/41687/0

Chimpanzee (pan trogloditus only) population nowadays : ~200,000
http://www.iucnredlist.org/details/15933/0

The discovery of fire by humans: a long and convoluted process | Philosophical Transactions of the Royal Society B: Biological Sciences http://rstb.royalsocietypublishing.org/content/371/1696/20150164

"We know that burning evidence occurs on numbers of archaeological sites from about 1.5 Ma onwards (there is evidence of actual hearths from around 0.7 to 0.4 Ma); that more elaborate technologies existed from around half a million years ago, and that these came to employ adhesives that require preparation by fire. We know that both early modern humans and Neanderthals had sophisticated fire technologies, at least some of the time."

The Invisible Fire Starters: A usewear-based approach to identifying evidence of fire production by Neandertals - Sorensen, Andrew - 2012 - Marster thesis
https://openaccess.leidenuniv.nl/handle/1887/18337

Fire tamed 1 million years ago [Wonderwerk Cave site in South Africa’s Northern Cape province ]
Before that, the earliest reliable evidences were considered to be 0.4 million years old.
https://blogs.scientificamerican.com/observations/humans-tamed-fire-by-one-million-years-ago/

Making Soapstone/Steatite as hard as flint ? after firing, at ~950°C ?

Soapstone / Steatite is marvelously easy to carve... and it can become hard and durable. Like clay, it has to be fired. Apparently for 1, 2 or 3 hours at ~950°C. Or, more interestingly : for 2 minutes only, at 1100 °C.

This is definitely worth a try. With very primitive means. Apparently the only technological requirement is knowing how to make big fires. Although, if we want 1100 °C, even for only 2 minutes, we'll probably need more than a big fire (some kind of kiln ? a strong and steady flow of air ?).

A few links and extracts : 

added November 2021, modified December 2021: https://www.academia.edu/35753853/Experimental_Studies_of_Harappan_Steatite_Carving_and_Firing_Techniques (Experimental Studies of Harappan Steatite Carving and Firing Techniques, 2012, in Pakistan Heritage, by Gregg Jamison). Firing for 1 minute at 1100°C is enough to harden steatite to a hardness of 5. Firing the steatite one minute longer, or one hour longer, makes no much visible difference : it puts the hardness at 6 instead of 5. Chert was used to scratch the surface of the steatite after firing. These experiments did not include firing at lower temperatures, for longer durations.

added 2020 11 11 : https://egyptmanchester.wordpress.com/2018/01/19/the-use-of-steatite-in-ancient-egypt/

Ancient Egypt used steatite (hardness of Mohs 1) for small intricately carved objects, then fired them, probably in kilns, until they crystallize into enstatite (hardness of Mohs 5.5, close to that of granite);

(Manchester Museum)

http://cameo.mfa.org/wiki/Steatite

"Native steatite is so soft it can be scratched with a fingernail, but baking results in dehydration and hardening of the stone. Some ancient steatite carvings were glazed then fired which produced a mineral (enstatite) hard enough to scratch glass."

http://iosrjournals.org/iosr-jhss/papers/Vol20-issue2/Version-5/K020256672.pdf
"[...] the so-called Harappan script [... signs ] have the most peculiar and elaborate iconographies of Indus Civilization. It is represented on many stamp seals of fired steatite and corresponding clay sealing terracotta tablets [...]"

https://www.harappa.com/slide/group-incised-baked-steatite-tablets
"A group of 16 three-sided incised baked steatite tablets, all with the same inscriptions, were uncovered in mid- to late Period 3B debris outside of the curtain wall."

https://www.harappa.com/sites/default/files/pdf/Kenoyer%202005%20Faience%20Workshop.pdf

2005 Steatite and Faience Manufacturing at Harappa: New Evidence from Mound

E Excavations 2000-2001

A paper by Kenoyer, that describes (in particular) an experiment made in 2001 at Madison, Wisconsin : 3 hours of firing, maintained 1 hour at 935°C by continuously fueling wood. 

"The experimental faience and steatite tablets were placed inside one canister, while a second

canister was overturned and placed on top as a lid. A narrow space was created between

the two canisters by using three splayed conical setters to raise the top canister slightly

above the lip of the first canister. This created a small, enclosed space that would be

insulated from the direct flame and ash. The canisters were placed on top of a layer of

wood fuel (pine and oak) and covered by additional fuel. After gradual heating, the entire

pile of fuel was ignited creating an extremely large bonfire. The tablets could be seen

through the space left open between the two firing canisters, and after approximately

three hours they reached a deep red orange color typical of relatively high temperatures.

Using a thermocouple (chrome-alumel) and digital pyrometer, the temperature of the

interior of the canister was documented at 935°C. By continuously adding fuel on top of

the canisters it was possible to maintain this temperature for about one hour, after which

the fire was allowed to die down."

From that, although kilns are mentioned in the paper, I understand that no kiln was used, but only "canisters" and "setters", put into a big pile of wood. Frustratingly, the article shows no drawing or photos of that experiment, so the reader is left alone to imagine what exactly the description refers to...

At least, we can find a few photos :

setters : https://www.harappa.com/search/site/setters

canisters debris :  https://www.harappa.com/indus3/251.html

experiment with canisters (for firing faience) : https://www.harappa.com/indus3/256.html

experimental canisters : https://www.harappa.com/indus3/254.html

The way to put the "setters" in place is not clear; and the way they put 2 canisters one on top of the other seems odd and unstable (no surprise that impurities did enter into it).

A much earlier publication (1997) by Miller, university of Wisconsin-Madison, explores ancient kilns (or what's left of them and how this can be interpreted) from the indus civilisation; 

https://www.harappa.com/sites/default/files/pdf/Miller_PotteryFiringStructuresKilns.pdf

http://community.ceramicartsdaily.org/topic/998-firing-rocks-with-clay-sculptures/
google image search, : images of Egyptian glazed steatite

http://www.nwssa.org/index.php?option=com_content&view=article&id=111:stone-corner-firing-soapstone-marapr-2002&catid=63:the-stone-corner&Itemid=62
Modern firing of soapstone, described; warnings about inclusions that can break a stone
Not very hot... but long... no hints about the hardness achieved : "to a high of no more than 500 degrees"; 24 hours of gradual heating, then 8 more hours.

http://archeosciences.revues.org/643
[about ancient beads from the sultanate of Oman] "We propose that steatite was used in the manufacturing process of the beads. The beads might have been made from soft steatite material and then hardened by firing at about 1000°C; the formerly soft beads thus became hard and durable. This hardening is due to the transformation of the steatite into synthetic enstatite which takes place at about 1000 °C."

http://www.academia.edu/11320048/_Cuire_des_statues_lusage_de_la_st%C3%A9atite_en_sculpture_%C3%A0_la_fin_du_Moyen_Empire_et_%C3%A0_la_Deuxi%C3%A8me_P%C3%A9riode_Interm%C3%A9diaire_GM_243_2014_p._23-32
(in french) Says that, around 1750 BC, Egyptians who were not rich enough had small sculptures made of steatite/sopastone, then baked at 900°C or higher so that they became as hard and durable as the statues made - from hardstones - for richer people.
« Cuire des statues » : l’usage de la stéatite en sculpture à la fin du Moyen Empire et à la Deuxième Période Intermédiaire.
"[...] Une cuisson à 900° C permet en effet de la durcir considérablement, de la rougir ou de la noircir (selon l’atmosphère de cuisson) [...] Sous l’effet de la chaleur, la pierre se déshydrate et, à partir d’une température de 900° C, se transforme en enstatite, d’un indice de dureté de 7 sur l’échelle de Mohs (au lieu de 1 pour la stéatite à l’état naturel) . Cette propriété est aujourd’hui utilisée par les artisans de la rive ouest de Louqsor pour produire des imitations de fritte, en enduisant d’une préparation à base de poudre de cuivre les pièces qu’ils ont réalisées en stéatite. Après cuisson à ciel ouvert, les reproductions d’amulettes et d’hippopotames sortent du foyer bleues, brillantes et très dures. [...]. Un simple four de quelques dizaines de centimètres de diamètre, creusé dans le sol, alimenté par un alandier et recouvert de briques a permis d’atteindre la température de 900° C en moins d’une heure. Un combustible particulièrement efficace et certainement aussi le moins onéreux pour cette opération s’est révélé être la bouse de vache séchée (utilisée encore aujourd’hui dans les campagnes égyptiennes). Lors d’une cuisson à ciel ouvert, en atmosphère oxydante, la stéatite rougit et obtient une couleur brun-rouge orangé, que l’on retrouve sur certaines statuettes de la XIIIe dynastie [...]. C’est probablement surtout une cuisson en atmosphère réductrice qui devait être utilisée. En effet, en refermant au bout d’une heure le four et en laissant se poursuivre la cuisson de la stéatite en enfumage pendant toute une journée, la surface obtenue était bien noire et dure. Un simple polissage a suffi ensuite à conférer à la pièce l’aspect luisant des statuettes du Moyen Empire."

http://annales.ensmp.fr/articles/1803-1804-1/82-84.pdf
(in french again) In the 18th century, artists were carving cameo from steatite/soapstone, then they baked them (to "red white" color) during 2 to 3 hours so that they become has hard as flint. They also had various ways for coloring the resulting stones. The paper also reports another experiment : making a paste with water and steatite/soaptsone powder, bake it (like clay), in hope of getting some hard rock : didn't work.

https://www.britishmuseum.org/pdf/Softstone%20in%20Arabia.pdf
"[... about small beads made from soft talc, then heated] The temperature at which enstatite crystallises is above 1200 C. This technology resembles that known from ancient India and Iran."
"[...] and other figurines (burials 634-638) made from a white heated form of steatite [...]"

http://link.springer.com/article/10.1007%2FBF00549373
The effect of firing temperature on properties of natural steatite and pyrophyllite
[The abstracts gives no practical new hint useful for prehistoric technology re-enactment : steatite hardens when heated above 900°C]
"Both materials were fired in hydrogen and air, over the temperature ranges of 950 to 1100° C and 1000 to 1150° C for the steatite and pyrophyllite, respectively. [...] The strength and hardness of the hydrogen-fired pyrophyllite was higher than its air-fired counterpart. The opposite result was observed in the steatite."

http://www.electronicsforu.com/EFYLinux/circuit/april2004/Steatite.pdf
a modern industrial process for firing steatite (but no information about the hardness obtained)

Cultural and social dimensions of the prehistoric Gulf Island soapstone industry - 1994 - Inge R. Dahm

http://summit.sfu.ca/system/files/iritems1/6548/b1696293x.pdf
Very interesting (artifacts description, culture, 200+km long distance exchanges, tools for carving soapstone, ...).
Apart from a few remarks like "this artifact appears to have been burnt", I couldn't find any discussion about a possible heat treatment of the soapstone artifacts and ornaments. Although this is a question that every reader would like to see answered : were those fragile artifacts hardened in some way, like in various other cultures, to withstand years of usage and... thousands of years in the ground ?
This being said, for many of this artifacs, especially labrets, softness may have been prefered to hardness: you don't want your teeth to be broken by a too hard stone labret. And the author regularly underscores the softness of the stone : maybe he verified it on most artifacts (? ... I didn't find any information about chemical analyses or hardness test).
About about physical properties, said to be "relevant to prehistoric soapstone carving", one information is the softness of the stone. And the only other information, rather irrelevant in prehistoric context is : "Fusability : Reaction to heat treatment. Soapstone will whiten and exfoliate when heated alone before a blowpipe and fuse to an enamel on the edges only". A few lines after that, another information that misses the point : "Soapstone can be heat treated to a hardness of 8 but will become brittle and will fracture or shatter on impact". Not very useful, because what we need to know is the amount of heat treatment - achievable with primitive means - that would confer some durability to (what variety and quality of) soapstone; and not the result of what appears extreme heat treatment (in other documents, heat treatments are said to harden soapstone to a hardness around 5 or 6).

Encyclopaedia Americana - 1800 - 1872
http://collections.nlm.nih.gov/bookviewer?PID=nlm:nlmuid-00110080RX11-mvpart 
On page 583 (579) , about Steatite... here is a pinnacle of imprecision : "exposed to heat it, becomes much harder". Other nevertheless interesting information : "the variety of  steatite called potstone is in hardness nearly the same as common steatite, but is more tenacious. [...] Steatite is not susceptible of a good polish; but its softness and tenacity [...] and its property of becoming hard by heat, render it a useful mineral in the arts. [...] The common steatite has even been employed for the purpose of engraving ; for, beeing easily cut when soft, it may be made to assume any desired form, and afterwards rendered hard by heat. It then becomes susceptible of a plolish, and may be variously colored by metalic solutions"

http://www.jstor.org/stable/124486
[protected content]
Glazed Steatite: An Investigation of the Methods of Glazing Used in Ancient Egypt  (Jun., 1989)
"Whichever glazing method is used for steatie [...] the body becomes very much harder"

http://pubs.usgs.gov/circ/1951/0095/report.pdf
[Talc Investigation in Vermont - Preliminary report - 1951 - US departement of the interior - geological survey]
page 2 : "The pure, dense, crypto-crystalline variety of steatite known as "lava grade" is valuable because it can be machined into intricate forms and then heat-treated to great hardness with negligible shrinkage."

https://archive.org/stream/talcdepositsofst08page/talcdepositsofst08page_djvu.txt
[TALC DEPOSITS OF STEATITE GRADE, INYO COUNTY, CALIFORNIA]
 "Lava-grade block talc is a variety of steatite dis- tinguished by its suitability for machining. It must be free of flaws and must not crack during firing. Formerly, lava-grade block talc was the only type of steatite used for insulators. Now, however, it is employed only in rela- tively small quantities for spacers in radar vaccuum tubes and for other specialized purposes. Since the discovery in the early 1920 's that pulverized talc could be used for making insulators, most steatite has been ground before firing. It is mixed with a binder, and pressed or extruded into the required shapes."

https://www.google.com/patents/US71919
[Letters Patent No. 71,919, dated December. 10, 1867. Henry Julius Smith, Boston]
"put the articles so formed in intimate contact with some kind of carbon, (I prefer finely-ground hone-coal or plumbago,) into a closed vessel, of suitable material for resisting heat, and submit the vessel and contents to heat for an hour or more, removing the same when a white heat has been reached. The articles are then found to be hard and tough. "
https://patentimages.storage.googleapis.com/pages/US71919.png

This corresponds probably to a temperature almost impossible to reach by prehistoric means.

Neanderthal superglue from birch bark - Experiments

Big buzz this summer 2017 about 3 different and successful experiments
 by P. R. B. Kozowyk, M. Soressi, D. Pomstra & G. H. J. Langejans.
Open paper on nature.com : https://www.nature.com/articles/s41598-017-08106-7
- Weight of the tar obtained = 9.6% of the weight of the bark (from Betula Pendula)
- Betula Alba would be the best species
- Several hours of burning with the "raised structure" technique [several hours : that's imprecise ! and from my experiments, I'm would tend to believe that 2 hours are more than enough]
- they seem to readily accept that "tar production is at least 200 thousand years old"

- Good news (obvious) : no real need for temperature control ; 

• Temperatures did vary during the experimentations, between less than 200°C and more than 400°C.
• Suitable temperatures with birch bark : between 250°C and 500+°C 
• "The ability to strictly control temperatures to a narrow range between 340 °C and 370 °C for tar production is thus not as necessary as previously thought"

They have an excellent illustration about the compared tar yield, compexity of the 3 methods and the need to control (or not) the temperature :

This being said, we can't say that the use of a digging stick is a "complexity" : it can be replaced by "digging hands", and is something that every animal can do. We probably invented the digging stick long before we invented fire, which may be the most complex thing here  :-)
OK, the complexity is in the number of steps needed... but do we really need to take this into account ? building a shelter requires a lot of steps; preparing one's tools for the next hunt requires a lot of steps; and even just making the spear for the next hunt requires lots of steps, knowledge and dexterity (finding a suitable piece of wood, preparing it, preparing a place for the spear point, finding flint or other suitable rock, knapping the rock, finding some adhesive or rawhide, hafting the spear point, ...). 

Links to videos (timelapses) of the best ("raised structure") of the 3 methods here:
 https://www.universiteitleiden.nl/en/news/2017/08/first-glue-neanderthals


A Method of Wood Tar Production, Without the Use of Ceramics
Grzegorz Osipowicz ; Reconstr. Exp. Archaeology EuroREA, 01/2005; 2:11-17.
Synthesis : http://www.keap.umk.pl/en/making-birch-tar-without-use-of-ceramics.html
Details : https://www.researchgate.net/publication/259583450_A_method_of_wood_tar_production_without_the_use_of_ceramics
There are interesting photos, and I would have loved seeing how was the glue accumulated at the bottom of the kiln, before its removal. The species of birch used in the experiment remains unknown.


Remarks, other links and other experiments
[no correct citations : a bunch of keywords, extracts and links]

From the above paper, we can guess that one primitive way of making glue from birch bark is not by producing tar first. In the described process, the tar mixes itself with charcoal : by "contamination" with carbonized birch bark.

Notes :
There are conflicting evaluations about the age of the piece of birch glue found at Königsaue : 40 000 years old or 80 000 years old. Older pieces of birch tar have been found in Italy (Campitello) : some say they are 200000 years old, others say that it's dubbious (see http://www.thesubversivearchaeologist.com/2012/02/of-birch-tar-hafts-and-caribou-fleshers.html).
From a short synthesis about the use of adhesives in Africa and Europe :
http://www.roceeh.net/fileadmin/images/Map_of_the_month/MoM_2010_12_Paleolithic_Adhesives.pdf



Still unclear to us ignorants... because we can read such different things here and there : Does the tar simply drip down, exuded in liquid form by the bark without going through a vaporized / gaseous state ? or does it condense itself from vaporized compounds ? or does it do both things, at various places in the kiln and at various stages of the process, depending on the temperature ?

Other apparently confusing elements :
"dry distillation", "destructive wood distillation", 300-400C, 340-400 °C, 220-280 °C, over 650°F [343°C], "released vapour is collected by a method which cools it down" , "wood tar is acquired during firing by it running through the holes into the smaller vessel placed underneath the big one" , "Without an airtight firing chamber, the wood tar would either evaporate or [...]", "limited air supply", Betula pendula Roth., Betula pubescens, ...

Much simpler techniques than "dry distillation" ?
http://www.academia.edu/11285848/To_see_a_world_in_a_hafted_tool_birch_pitch_composite_technology_cognition_and_memory_in_Neanderthals
"in simple covered pits (Pawlik 2004) or underneath stones inside a fire (Palmer 2007). It may even be possible through holding bark tightly wrapped around a stick inside the heart of a fire (Knul, pers. comm. 2011)".

As technologically simple as traditional charcoal making ?
http://www.continuitas.org/texts/benozzo_distillation.pdf
"[about (the very primitive) charcoal making in the XIX-XX in Itlay; page 35] the production of pitch was one of the secondary activities related to the making of charcoal (it was employed for covering roofs, or as a glue for tools, and the carbonai used to sell it together with charcoal"


Links and Experiments :

Grzegorz Osipowicz continues to experiment, and tries different types of kilns
http://www.academia.edu/4898914/New_experiments_with_a_mehod_of_birch_tar_production_without_the_use_of_ceramics

Neanderthal Superglue [2013; video]
https://www.youtube.com/watch?v=Dv81adCRQ2s
Shows a primitive process which result - after 8 hours of burning - is a very faint layer of tar on a small stone; no liquid.

Neanderthals 'used glue to make tools' ; Saturday, 19 January, 2002, 08:00 GMT
http://news.bbc.co.uk/2/hi/science/nature/1766683.stm
Keywords : Dr Dietrich Mania; Germany; Königsaue; Harz Mountains; Friedrich-Schiller University ; European Journal of Archaeology

"A sticky fingerprint on a fossilised blob of wood"
http://www.freerepublic.com/focus/f-news/608179/posts
keywords : Aschersleben; Harz Mountain; Heinrich Wunderlich; Professor Dietrich Mania of Freidrich-Schiller University in Jena ; more than 80 000 years old

Neanderthals Clever Enough To Make 'Superglue'
http://www.freerepublic.com/focus/fr/602648/posts
Extract :"The research, carried out at the Doerner-Institut in Munich, found the pitch was a birch pitch, which can be only be produced at temperatures of 300-400C"
keywords : Discovered in a lignite mining pit in the Harz mountains in Germany. Professor Chris Stringer, Natural History Museum in London. Professor Dietrich Mania of Freidrich-Schiller University in Jena

High-Tech in the Middle Palaeolithic: Neandertal-Manufactured Pitch Identified
http://eja.sagepub.com/content/4/3/385.abstract
European journal of archaelogy
keywords : Johann Koller,Ursula Baumer Doerner-Institut, München, Germany; Dietrich Mania , Friedrich-Schiller-Universität Jena, Germany

Neanderthals Defy Stereotypes
By Evan Hadingham ; Posted 01.09.13; NOVA
http://www.pbs.org/wgbh/nova/evolution/defy-stereotypes.html
Extracts : [...] distilling pitch from birch bark requires an oxygen-free environment and sustained temperatures of over 650° F [...] first discovery was made in 1963 at Kínigsaue, in then-East Germany. [...] Two small, hardened lumps of black material were found [...] one bearing a fingerprint and the other the impression of a wooden haft or handle. [...] In 2001, the lumps were dated to at least 40,000 years ago [...] birch bark pitch produced by the dry distillation process. Much older evidence was found at the Campitello quarry in central Italy. [...] two large lumps of black pitch, which covered the end of two stone flakes crafted in a typical Neanderthal style. The Campitello find dates back over 200,000 years [...] A third Neanderthal site at Inden-Altdorf, overlooking the Inde River in Germany and dating to around 128,000 to 115,000 years ago, features more than 80 stone tools flecked with black material, but the chemical analysis indicating that this was distilled pitch requires further confirmation.
[...] the team proposed that the Neanderthals had invented the following procedure: first, wrap a long strip of birch bark around a small pebble so that it forms a cigar-shaped roll. Next, dig a narrow pit, then set light to one end of the roll and place the burning end at the bottom of the pit. In the confined space at the bottom of the pit, the smoldering bark quickly uses up oxygen and causes the pitch to "sweat," or condense, out of the roll of bark onto the surface of the pebble. While still hot, the pitch is a sticky liquid that can be used immediately as glue.
[...] Although German experimental archaeologist Friedrich Palmer succeeded in earlier published experiments, in the NOVA program, he fails to produce more than a thin smear of pitch. In 2010, another team reported success by a variation on the technique: lay strips of bark on a flat stone surface, cover them with a couple of inches of sand to exclude oxygen, then build a fire on top. After a little over an hour, the team dug up the stone and found that enough pitch had dripped onto its surface to haft two or three spears or tools.However, the team succeeded easily on their first attempt only because they had a thermometer to judge if the fire was hot enough.[...] Archaeologist Wil Roebroeks, who witnessed Palmer's NOVA experiment, comments that its failure underscores the complexity of the process,[...]

Sticking with Neanderthals: Identifying Neanderthal Mastics and their Signatures
Joseph Walsh; Advisor: Bruce Hardy, PhD., David Heithaus
http://biology.kenyon.edu/HHMI/posters_2014/walshj.pdf

Ça colle pour l'homme de Neandertal
Par Sylvie BRIET — 22 janvier 2002 à 21:45
http://www.liberation.fr/sciences/2002/01/22/ca-colle-pour-l-homme-de-neandertal_391193
Extracts : [... ] En 1963, Dietrich Mania, paléontologue à l'université d'Iéna, découvre des outils et morceaux de poix datant de l'époque de Neandertal dans une carrière de lignite au nord-est des montagnes du Harz, près de Königsaue (Allemagne).[...] L'un des morceaux comporte une empreinte de doigt mais également la marque d'une lame de silex et celles de cellules de bois: ce morceau de poix, utilisé comme adhésif, fixait un manche en bois à une lame de couteau en silex. Tout le matériel découvert (comprenant d'autres pièces de bois et outils en silex) fut transféré au Landesmuseum à Halle. Sans être analysé plus avant car les techniques n'existaient pas.Trente-trois ans plus tard, le matériel est envoyé à l'institut Doerner. Des premiers résultats furent publiés en 1999. Cette fois, Johann Koller et Ursula Baumer ont établi la composition chimique [...] origine biologique [...] découvert que le niveau de bétulin (Betula verrucosa) est très élevé dans leurs morceaux de poix, comme dans l'écorce de bois de bouleau. [...] pour fabriquer une glue de cette qualité, il a fallu chauffer l'écorce dans une fourchette de température très étroite: entre 340 et 400 °C. [...] L'abondance du matériel annexe, les outils multiples suggèrent qu'il existe deux cultures sur ce site. L'une d'elles peut être attribuée aux premiers Homo sapiens modernes, la seconde revient clairement aux Néandertaliens. Restent des incertitudes sur les datations. Dietrich Mania, le paléontologue qui a découvert le site, n'a aucun doute sur l'âge des couches géologiques qui datent de 80 000 ans. Les morceaux ont été envoyés à Oxford (Grande-Bretagne) pour une datation au radiocarbone qui a donné 44 000 et 48 000 ans! La trop faible concentration en carbone pourrait expliquer cette différence et les chercheurs penchent pour la date géologique. [...]
European Journal of Archaeology de décembre 2001.

Neanderthal Glue Makers
[Video, 2008, National Geograhics]
https://www.youtube.com/watch?v=q7YT2HxWPVU
Claims to have a good idea of how Neandertals could have made glue from birch bark.
Illustrates the first steps, but doesn't show the end of the process nor success.
Evokes Native American Tribe in Canada having an ancestral technique for that, but doesn't name it, unfortunately...
keywords : Museum of Halle; fragment of ice age adhesive found in the 1960 in Königsaue in eastern germany; Dr Christian Heinrich Wunderlich, "no scientist has succeeded in making this pitch glue with the material Neandertals could have used"

Genotoxicity Assessment of Birch-Bark Tar—A Most Versatile Prehistoric Adhesive
http://file.scirp.org/Html/19560.html
Extract: "heating (pyrolysis) the bark of birch trees (e.g. European white birch Betula pendula Roth) under reducing conditions with limited air supply and a temperature of over 300˚C, the distillation product is an odorous dark-brown viscous pitch (Dudd & Evershed, 1999)."

Experimental explorations into the aceramic dry distillation of Betula pubescens (downy birch) bark tar.
First online: 21 June 2013.Peter Groom,Tine Schenck,Grethe Moéll Pedersen
http://link.springer.com/article/10.1007/s12520-013-0144-5?no-access=true
Extract : "[...] Though the experiments did not successfully produce tar as a finished product, they did lead to a better understanding of the dry distillation process [...]"

Traditional Glue, Adhesive and Poison Used for Composite Weapons by Ju/’hoan San in Nyae Nyae, Namibia. Implications for the Evolution of Hunting Equipment in Prehistory
 Lyn Wadley , Gary Trower , Lucinda Backwell , Francesco d’Errico
PLOS; Published: October 28, 2015; DOI: 10.1371/journal.pone.0140269
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0140269
Extract : "Western European Neanderthals heated birch bark for glue by Marine Isotope Stage 6 (MIS 6, that is, ~200,000–130,000 years ago) at the Campitello quarry site in Central Italy [1,2]. Stone tools from an occupation ~120,000 (120 ka) years old, in Inden-Altdorf, Germany, were hafted with birch bark pitch [3] and it was also discovered at Königsaue, Germany, where the geological-stratigraphic context suggests ages older than 80 ka [4]."


And here are my own experiments, not all failed
https://www.youtube.com/playlist?list=PL3DB4AC65A3ADEE03


More documents

Using Organic Materials in prehistory
Universtity College of London
https://www.ucl.ac.uk/archaeology/studying/undergraduate/courses/coursehandbooks/ARCL2041_organic_materials.pdf
[not about Neandertals] Werner Pfeifer describes an open distillation process  and a closed distillation process; in both cases there are similarities with the kiln of Grzegorz Osipowicz ; but the result is very different : liquid tar, not hard glue.

Wood Tar in The Dnieper and Elbe Communities - VI-II Millenium BC
Slavomir Pietrzak; Baltic-Pontic studies; 2012 
https://repozytorium.amu.edu.pl/bitstream/10593/13021/1/BPS-17_S_Pietrzak_WOOD%20TAR%20IN%20THE%20DNIEPER%20AND%20ELBE%20COMMUNITIES-VI%20%E2%80%93%20II%20MILLENIUM%20BC.pdf
[not about Neandertals]

When did humans learn to boil ?
John D. Speth, 2014
http://www.paleoanthro.org/media/journal/content/PA20150054.pdf
Humans may have, very early, boiled their food in skins, paunches, bark containers, by direct heating over a flame (without using heated stones, nor ceramic vessels). These techniques have been described in a number of Native American cultures. [see pages 57 to 59, in "Boiling in perishable containers without using heated stones"].
About birch glue : 
"Birch tar can only be produced by a process of destructive (dry) distillation, in the absence of oxygen, and with temperatures maintained for several hours between a minimum of 340 ºC and a maximum of about 400 ºC (Koller et al. 2001; Peters et al. 2005: 335–337). [...]  No one to my knowledge has yet adequately figured out how Neanderthals would have accomplished this complex feat of pyrotechnics without the aid of metal or ceramic containers (see Osipowicz 2005; Peters et al. 2005: 336–337; Palmer 2007; Meijer and Pomstra 2011; Groom et al. 2015)." [[what ? Osipowicz shows a way to do it, actually]]
The bibliograhy related to these extracts :
Groom, P., Schenck, T., Moéll Pedersen, G. 2015. Experimental explorations into the aceramic dry distillation of Betula pubescens (downy birch) bark tar. Archaeological and Anthropological Sciences 7, 47–58.
Koller, J., Baumer, U., Mania, D. 2001. High-tech in the Middle  Palaeolithic: Neandertal-manufactured  pitch identified. European Journal of Archaeology 4, 385–397.
Meijer, R., Pomstra, D. 2011. The production of birch pitch with hunter-gatherer technology: a possibility. Experimentelle Archäologie in Europa, Bilanz 2011, 199-204.
Osipowicz, G. 2005. A method of wood tar production, without the use of ceramics. euroREA  2, 11–17.
Palmer, F. 2007. Die entstehung von birkenpech in einer feuerstelle  unter  Paläolithischen  bedingungen. Mitteilungen der Gesellschaft für Urgeschichte 16, 75–83.
Peters, K.E., Walters, C.C., Moldowan, J.M. 2005. The Biomarker Guide, Vol. 1. Biomarkers and Isotopes in the Environment and Human History. 2nd edition. Cambridge University Press, Cambridge.

Bâton de jet Gaulois - Urville-Nacqueville, Manche, France - Rainuré comme certains boomerangs et kylies australiens et bâtons de jets amérindiens

Etude et expérimentations autour de la découverte d'un bâton de jet gaulois 

sur le site d’Urville-Nacqueville (Manche)

Luc Bordes, Anthony Lefort, François Blondel et Thierry Meinel

 

http://revedeboomerang.free.fr/baton-urville2.pdf

 

Bâton de jet ; chasse aux oiseaux ; renforts en fer ; rainures longitudinales

100 av. J.C.

Trouvaille archéologique unique en France : en 2010

Comparaison avec d'autres bâtons de jets / boomerangs / kylies ; Europe et monde

 

Rainures purement décoratives ... Quels arguments ?

Les auteurs prennent pour acquis que les rainures longitudinales sont purement décoratives. 

En même temps ils soulignent la présence de rainures du même type sur des boomerangs amérindiens et australiens. Alors... naturellement ... frustration manifeste du lecteur qui veut un début de "preuve" que cette convergence est uniquement décorative et non fonctionnelle.

Il existe peut-être un argument simple, dans ce cas précis où l'on affirme 

que ce boomerang sans retour était utilisé dans un environnement humide : 

les rainures mouillées ne joueraient plus leur rôle. 
Il m'est arrivé de faire l'expérience dans un environnement boueux : 

dès le second jet, le vol de mon boomerang sans retour s'est dégradé 

(alourdi, les rainures boueuses, ...).

 

Il existe au moins une étude, résultat d'expérimentation en soufflerie, sur l'efficacité aérodynamique des rainures de boomerangs / bâtons de jets australiens. 

Nelson, Reymond Charles. 'Groovy' Aerodynamics in Pre-European Australia.

Australian Journal of Multi-disciplinary Engineering, Vol. 2, No. 1, 2004: 1-7. 

 

On trouve l'article sur internet, mais il est payant. Je l'ai acheté, lu et ... perdu... En fait, il n'offrait pas de preuve définitive, mais sa conclusion suggérait assez nettement une fonction aérodynamique pour ces rainures, pourvu qu'elles respectent certaines conditions. 

 

La présentation de l'article est beaucoup plus catégorique (commerce oblige...) : 

 "[...]  Wind tunnel tests show large drag force reductions in the case of throwing sticks and large lift force increases in the case of boomerangs. The fluting alone is responsible for the improved performance.[...]" 

 (http://search.informit.com.au/documentSummary;dn=520325129598400;res=IELENG

ou http://www.tandfonline.com/doi/abs/10.1080/14488388.2004.11464717)