How to Build a Medieval City

September 20, 2011 by kris de decker Filed Under: Architecture, Books & Reference, History, Random

how to build a medieval city

The “Dictionnaire raisonné de l’architecture française du XIe au XVIe siècle” is an overwhelming reference work consisting of 9 books (some 5,000 pages in total) on medieval and renaissance architecture in France. It is written in French, as you already suspected, but the detailed illustrations make it worthwhile for all architecture and history devotees. There is really all you need to know to build, for instance, a gothic cathedral, including the gargoyles. The work appeared in 1856 and was written by Eugène Viollet-le-Duc, an architect known for his restorations of medieval buildings. The separate volumes can also be found on the Internet Archive.

 

Jua Kali: Innovation in Kenya’s Informal Economy

September 19, 2011 by kris de decker Filed Under: Africa, DIY, Random

Jua Kali Innovation in Kenya’s Informal Economy

Wandering through winding alleys dotted with makeshift worksheds, one can’t help but feel clouded by the clanging of hammers on metal, grinding of bandsaws on wood, and the shouts of workers making sales. But soon it becomes clear that this cacophony is really a symphony of socioeconomic interactions that form what is known as the informal economy.

In Kenya, engineers in the informal economy are known as jua kali, Swahili for “hot sun,” because they toil each day under intense heat and with limited resources. But despite these conditions, or in fact because of them, the jua kali continuously demonstrate creativity and resourcefulness in solving problems.

“Making Do: Innovation in Kenya’s Informal Economy”, Steve Daniels, 2010. Full book online here and here. Hat tip to Gabriella Rubin. Related: Cameroon blacksmiths.

Making a Dugout Canoe Using Stone Tools and Fire

September 15, 2011 by kris de decker Filed Under: Boats, DIY, Fire, Forestry equipment, History, Primitive technology, Random, Trees, Wood

Making a Dugout Canoe Using Stone Tools and Fire

“The Dugout Canoe Project (.pdf) began as an experiment to use traditional Native American technologies. Archaeologists are reliant on just a few ethnohistoric sources that mention how Native Americans made dugout canoes using stone tools and fire. Numerous contemporary examples of dugouts exist, particularly Plimouth Plantation’s Wampanoag Indian Program, made by burning and scraping out logs. However, to the best of our knowledge, no one has attempted to fell a tree using only stone tools and fire. We wanted to see if we could cut down a live tree using these technologies, something that may not have been done in this area for several hundred years.”

“Dugout canoes are probably the first type of boat ever made. People from all over the world made dugouts. They were widely used in North America before the arrival of Europeans. Dugout canoes were made by Native Americans across North and South America for transportation and to hunt fish with a spear, bow and arrows, or with hooks made from antler or bones. In Eastern North America, dugout canoes were typically made from a single log of chestnut or pine. Carefully controlled fires were used to hollow out these logs. The fires were extinguished at intervals to scrape out the burned wood with wood, shell or stone tools, giving the canoes a flat bottom with straight sides.”

Courtesy of the Fruitlands Museum. More posts on primitive technology.

Trees as Indicators of Prevailing Wind Direction

September 9, 2011 by kris de decker Filed Under: Random, Trees, Wind Power, Wind turbines, Windmills

trees as indicators of wind direction“In mountainous areas, winds are often complex and the available wind data are limited and provide little information on wind direction. One technique for determining the mean wind direction is tree flagging. Trees have been used for hundreds of years as an ecological indicator of wind direction, wind exposure and as a measure of the severity of wind and ice damage. This handbook will describe techniques for ‘reading’ the information written on the trees by wind.”

“Flagged trees only reflect the prevailing wind direction of the strongest winds, which may occur during only part of the year. Seasonal variations in the wind have a pronounced effect on the type of wind deformation and these effects are characterized in this handbook. Techniques for estimating the mean annual wind speed have been developed using indices of wind effects on trees. These indices have been calibrated on two widely distributed species of conifers. The main conclusions are that trees provide a simple, inexpensive and quick method for identifying promising locations where more detailed measurements can verify the wind potential.”

Trees as an indicator of wind power potential (.pdf), John E. Wade & E. Wendell Hewson, 1979.
Vegetation as an indicator of high wind velocity (.pdf), DOE report, John E. Wade & R.W. Baker, 1977

More low-tech wind power.

Making a Blade out of Homemade Steel

September 9, 2011 by kris de decker Filed Under: DIY, Metal working, Random

making a blade out of home made steel

“From Dust to Edge is the documentation of a long journey in the efforts of making a blade out of homemade steel. My interest in blades started with the legendary Japanese katana and as a result of wanting to learn more about how they were made I ended up becoming a bladesmith.

I combined the traditional Japanese techniques and the current knowledge of the Western smith in this pictorial representation. The project will be divided in several sections. It is primarily a visual description through photographs.”

Via Kevin Kelly.

Continuously Variable Bicycle Gear Hub

September 7, 2011 by kris de decker Filed Under: Bicycles, Bikes, Gears, Random, Travel

Continuously Variable Bicycle Gear Hub“The NuVinci hub is a unique internal gear hub in that it utilizes a continuously variable planetary (CVP) transmission. This means that the hub does not have specific gears but instead can be dialed in to any particular gearing in it’s capable range. You can think of it sort of as an analog radio tuner as opposed to a digital tuner with its particular increments.”

“When compared to traditional continuously variable transmissions (CVTs), the NuVinci CVP is less complex, has considerably fewer parts, offers more stable control and scalability across product lines, is better packaged, and is less expensive to manufacture and assemble.”

The NuVinci N360. How it works. Reviews of 2007 and 2010 models: 1 / 2 / 3. The gear is used on the flywheel bicycle mentioned last week and can also be applied in light electric vehicles and wind turbines. Thanks, Johan.