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Coracle
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It was a great invention. I suppose the Construction tech applies to this.
A structural masonry material made by mixing broken stone or gravel with sand, cement, and water and allowing the mixture to harden into a solid mass. The cement is the chemically active element, or matrix; the sand and stone are the inert elements, or aggregate. Concrete is adaptable to widely varied structural needs, is available practically anywhere, is fire resistant, and can be used by semiskilled workers. 1
The use of artificial masonry similar to modern concrete dates from a remote period but did not become a standard technique of construction until the Romans adopted it (after the 2d cent. B.C.) for roads, immense buildings, and engineering works. The concrete of the Romans, formed by combining pozzuolana (a volcanic earth) with lime, broken stones, bricks, and tuff, was easily produced and had great durability (the Pantheon of Rome and the Baths of Caracalla were built with it). Enormous spaces could be roofed without lateral thrusts by vaults cast in the rigid homogeneous material. 2
Scientifically proportioned concrete formed with cement is an invention of modern times; the name did not appear until c.1830. Modern portland cement has revolutionized the production and potentialities of concrete and has superseded the natural cements, to which it is vastly superior. The component materials of concrete are mixed in varying proportions, according to the strength required and the function to be fulfilled; the proportions were first worked out by Duff Abrams in 1918. The ideal mixture is that which solidifies with the minimum of voids, the mortar and small particles of aggregate filling all interstices. A typical proportioning is 1:2:5, i.e., one part of cement, two parts of sand, and five parts of broken stone or gravel, with the proper amount of water for a pouring consistency. A simple test called a “slump test” is used to confirm the proportions and consistency of the mixture, and it is then poured into wood or steel molds, called forms. Concrete usually takes about five days to cure, or reach acceptable hardness, but a technique called steam saturation can shorten that curing time to less than 18 hours. A wide variety of additives allow the concrete to harden faster or slower, resist scaling, or adopt the final shape more easily. 3
Concrete used without strengthening is termed mass, or plain, concrete and has the structural properties of stone—great strength under compressive forces and almost none under tensile ones. F. Joseph Monier, a French inventor, found that the tensile weakness could be overcome if steel rods were embedded in a concrete member. The new composite material was called reinforced concrete, or ferroconcrete. It was patented in 1857, and a private house in Port Chester, N.Y., first demonstrated (1857) its use in the United States. It is now rivaled in popularity as a structural material only by steel. Concrete reinforced with polypropylene fibers instead of steel yields equivalent strength with a fraction of the thickness. Reinforced concrete was improved by the development of prestressed concrete—that is, concrete containing cables that are placed under tension opposite to the expected compression load before or after the concrete hardens. Another improvement, thin-shell construction, takes advantage of the inherent structural strength of certain geometric shapes, such as hemispherical and elliptical domes; in thin-shell construction great distances are spanned with very little material. The perfecting of reinforced concrete has profoundly influenced structural building techniques and architectural forms.
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lorddread
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Indianapolis, the Speed Capital of the World
Feb 2002
time: 23:19
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[QUOTE] Originally posted by Sagacious Dolphin
quote:
If we hadn't had the dark ages, we would probably be living on the moon and exploring Mars. That's how much science we lost |
So was Europe the only centre of technology. I don't doubt the statement has truth, but I thought the knowledge was only lost in Europe and survived elsewhere to be rediscovered (as opposed to re-invented) during the renaissance.
QUOTE]
Actually, the dark ages hit almost everywhere in the world with 200 years. China, Central America, Japan, Egypt, and even part of South America experienced their own Dark Ages. In China, it came and went quick, Japan's is believed to have last several hundred (300+/-) years. South America and Central America's cultures never recovered.
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Kramerman
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UT, Austin - The live music capital of the world
Jun 2002
time: 23:19
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That is very correct. I saw that same program you were referring to, or at least a similar one. It said how we could be hundreds of years technologically advanced to how we are if it weren't for the fall of the increasingly decadent Roman empire and dark age that ensued(which did, as mentioned earlier, hit the whole world, and not just Europe). All lost Technology had to be relearned and it was durring the high middle ages and renassaince that most of this was done. Luckly the Arabs were able to perserve some of Greece's and Rome's works, both scientific and artistic. Humanity didn't finally start to gain ground and learn new techs until the Enlightenment .
One thought to chew on is that some Greek guy, not sure what his name was or if he was even Greek, but this Mediterrainian guy had developed a steam engnige and it was used to open the doors of a temple. It was a novolty that made people awe-struck at the time. Unfortunately slaves were so prevelant at the time and for many other reasons, this steam sngine was never developed and the tech was eventually lost after the dude's death. But, just think, it could of been possible to have the Industrial Reveloution right then and there. In thte pursuit to make businesses more profitable, as we do today, science would of boomed and we could very well be 1500-2000 years ahead technologically compared to how we are now.
Kman
P.S. I read somewhere that the Romans mixed some kind of volcanic ash found in northern italy into their concrete which increased its strength very much. In fact, until recently scientists could not explain why Roman concrete seemed to be stronger than modern non-reinforced concrete up until the 1920s. Then the ash technique was discovered and gave valuable insight into the stregnth properties of concrete. So the Romans (and all Ancients, for that matter) were still teaching us new things even into modern times. And the Greek analog computer they discovered, that just amazes me that they had such advancements more than 2000 years ago.
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Kramerman
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UT, Austin - The live music capital of the world
Jun 2002
time: 23:19
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quote:
A small scale industrialisation is a contradiction in terms. The reason that factories were setup was to serve the growing demand for products. If the demand is not there, factories would not be profitable and the revolution not take place. |
You misunderstand me, small scale in comparison to our industrial revolution, but in proporton it would be relatively the same. In other words its overall production would be nothing compard to what ours was, but in proportion to its population it would produce about the same per prerson in order to support the demand that drives it.
quote:
Inventions do not lead society, no matter how ingenious they are, society selects the inventions that are suited to there current situation. |
no, that is not what i meant, your statement is generally true. After all, that is why the steam engine didn't spark the industrial revolution then, due to the society was laregely slave oriented (this one reason why the IR came to America later than Europe, and the the North much sooner than the south). Listen, now adays, when a business wants to get ahead, to make more money in the instinctive capitolist spirit of a human being, they will try to improve upon what they had. This is what led to the continual improvements made to the steam ingine design and to applications of it during the 19th century. James watt originally made his engine to pump water or something out of mine shafts. It was then modifid and improved to use as powering factories, boats, and trains. the idea of automated power was there, and led to the idea and eventual developement of internal combustion and all of the applications there of. Inventions are made to make life better (Technology is defined as science that is applied for use in everyday life) and though they do not directly lead society, because they are made to accomodate it, they do shape it and prepare it for its future evolutions. This is how an early IR would of sparked a technological revolution as well. If you think about it, there has been more technological growth since the IR (though this is due to many other and sometimes more important reasons too) then in the rest of the history of civilization combined.
I know my writting is hard to understand, but my idea makes since, though it is only hypothetical. A IR didn't happen then for many reasons, and depending on certain changes in events throughout history, an IR could have not have happened until several centuries from now. Many countres are just now under going this IR and some have yet too still, and thi due to their societies, like you said.
Kman
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Dauphin
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Caught in a tuna net
Jan 1970
time: 05:19
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I think we are basically singing from the same hymn sheet, but have slightly different views on one or two points.
quote:
In other words its overall production would be nothing compard to what ours was, but in proportion to its population it would produce about the same per prerson in order to support the demand that drives it |
My argument is that you lose the economy of scale if you scale down the size of the revolution.
With regards technology and society, there are several prerequisites required for the industrial revolution, and so the chances of ancients having a revolution was as much dependent on technology as on demographics, social views/civil desires, economics, transport, government etc. I think we are in agreement as to this. What my point was that even if the steam engines potential was recognized by people other than its inventor it still would not have been realised. It would have been a pipedream until all the other prerequisites were far enough developed.
After all the steam engine was reinvented in the 1650's, redesigned by Newcomen in the early 1700's and revolutionised by Watt in the 1770s. Yet the full scale use of the steam engine in industry and transport was not until the 1820's.
Also, considering the industrial revolution started in 1771 (Arkwrights first Cotton Mill in Cromford) and used waterwheels and not steam engines, it shows that the steam engine was filling a role to supply power for the revolution, rather than sparking the revolution.
We are expressing things differently, but I think we are making the same point. 
Last edited by Dauphin on 06-07-2002 at 14:53
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27-05-2002 11:17
Actually I wasn't refering to the dome or concrete even. ABout 80% of everything that had been learned in the previous centuries was lost starting in about 520 AD. This is the reason this period is called the dark ages.
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