This very interesting article is a great read about the history of Chinese bamboo drilling by Oliver Kuhn.
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At some point around 2,000 years ago the leap from hand and shovel dug wells to percussively drilled ones was made. By the beginning of the 3rd century AD, wells were being drilled up to 140m deep. The drilling technique used can still be seen in China today, when rural farmers drill water wells. The drill bit is made of iron, the pipe bamboo. The rig is constructed from bamboo; one or more men stands on a wooden plank lever, much like a seesaw, and this lifts up the drill stem a metre or so. The pipe is allowed to drop, and the drill bit crashes down into the rock, pulverizing it. Inch by inch, month by month, the drilling slowly progresses.
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A major breakthrough was achieved around 1050 AD, allowing deeper wells, when solid bamboo pipe was replaced by thin, light, flexible bamboo “cable”. This dramatically lowered the weight that needed to be lifted from the surface, a weight that increased with the depth being drilled. By the 1700s Sichuan wells were typically in the range of 300 – 400m deep
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One bamboo pipe line would take away the brine, and others the gas. The 2,000 year plus Sichuan salt industry has drilled approximately 130,000 brine and gas wells, and 10% of those were in the immediate Zigong area. Zigong has a cumulative gas production over this period of over 30 billion cubic metres. The area continues to be a major salt producer, and many of the historical wells are still in production.
An ancient sketch originally from “The Annals of Salt Law of Sichuan Province”. A “Kang Pen” drum is seen in the centre foreground, with gas pipes directly feeding the salt stoves on the right. At the top, brine from a remote well is being carried in buckets by men, who feed it into a bamboo pipeline that runs down to the stoves. One of the carriers is being paid at top left, and it appears that a blow out is depicted on a new well being drilled.
(from Zhong & Huang)
As recently as the 1950s there was still over 95km of bamboo pipeline in operation in the Zigong area.
Related: Research on Ancient Roman Concrete Will Allow the Creation of More Durable and Environmentally Friendly Concrete – Why did China’s Scientific Innovation Stop? – Hyperloop – Fast Transportation Using a Better Engineering Solution Than We Do Now
Chart showing global installed wind energy capacity by Curious Cat Science and Engineering Blog, 
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USA Losing Scientists and Engineers Educated in the USA
Posted on March 20, 2009 Comments (7)
The USA continues to lose ground, in retaining the relative science and engineering strength it has retained for the last 50 plus years. As I have said before this trend is nearly inevitable – the challenge for the USA is to reduce the speed of their decline in relative position.
A new open access report, Losing the World’s Best and Brightest, explores the minds of current foreign science and engineering students that are studying in the USA. This is another in the list of reports on similar topics by Vivek Wadhwa and Richard Freeman. And again they point out the long term economic losses the USA is setting up by failing to retain the talent trained at our universities. It is a problem for the USA and a great benefit for countries like India and China.
“Foreign students receive nearly 60% of all engineering doctorates and more than half of all mathematics, computer sciences, physics and economics doctorates awarded in the United States. These foreign nationals end up making jobs, not taking jobs,” said Wadhwa. “They bring insights into growing global markets and fresh ideas. Research has shown that they even end up boosting innovation by U.S. inventors. Losing them is an economic tragedy.”
According to the study’s findings, very few foreign students would like to stay in the United States permanently—only 6% of Indian, 10 percent of Chinese and 15% of Europeans. And fewer foreign students than the historical norm expressed interest in staying in the United States after they graduate. Only 58% of Indian, 54% of Chinese and 40% of European students wish to stay for several years after graduation. Previous National Science Foundation research has shown 68% of foreigners who received science and engineering doctorates stayed for extended periods of time, including 73% of those who studied computer science. The five-year minimum stay rate was 92% for Chinese students and 85% for Indian students.
The vast majority of foreign student and 85% of Indians and Chinese and 72% of Europeans are concerned about obtaining work visas. 74% of Indians, 76% of Chinese, and 58% of Europeans are also worried about obtaining jobs in their fields. Students appear to be less concerned about getting permanent-resident visas than they are about short-term jobs. Only 38% of Indian students, 55% of Chinese, and 53% of Europeans expressed concerns about obtaining permanent residency in the USA.
On the tonight show yesterday, President Obama said
And if we’re rewarding those kinds of things that actually contribute to making things and making people’s lives better, that’s going to put our economy on solid footing. We won’t have this kind of bubble-and-bust economy that we’ve gotten so caught up in for the last several years.
Eric Schmidt, Google CEO, recently expressed his frustration with the policies discouraging science and engineering graduates staying in the USA after they complete their education.
Related: Invest in Science for a Strong Economy – Science, Engineering and the Future of the American Economy – USA Under-counting Engineering Graduates – Losing scientists and engineers will reduce economic performance of the USA – Diplomacy and Science Research
Categories: Economics, Engineering, Science, Students
Tags: Career, China, commentary, Economics, economy, Engineering, engineering education, entrepreneurship, India, John Hunter, open access paper, quote, Science, USA