Pigeon Towers: A Low-tech Alternative to Synthetic Fertilizers

pigeon-towers-iranPhoto credit: Bekleyen, A. (2009). The dovecotes of Diyarbakır: the surviving examples of a fading tradition. The Journal of Architecture, 14(4), 451-464..

Many societies, ancient and contemporary, have innovated ways of supplying their fields with fixed nitrogen and phosphorus—two crucial ingredients for crop productivity. One is crop rotation, which alternates nitrogen-fixing and nitrogen-exhausting crops. Farmers around the world make use of chickens, ducks, and geese to add “fresh” guano to their fields. Cattle manure is another useful alternative—although it often lacks in phosphorus. Much more labor intensive than simply adding fossil-fuel derived synthetic fertilizer, these practices tend to build up soil, limit greenhouse gas emissions, and lead to less run-off into rivers, lakes, and oceans.

Persian pigeon towers are one of the more elegant solutions to the nitrogen-phosphorus problem. These are essentially castles built for thousands of wild pigeons, strategically placed in the middle of the fields. Their droppings were shoveled up once a year and sold to nearby farmers. While most pigeon towers existing today are in disrepair, the oldest still standing are dated to the 16th century (but they are assumed to have existed over 1,000 years ago) and helped fuel the cultivation of Persia’s legendary orchards, melons, and wheat production.[1] [Read more…]

Sail the World’s Largest Viking Ship from Europe to America

viking ship“Draken Harald Hårfagre (that’s “Dragon Harald Fairhair” in English) is a modern interpretation (rather than an accurate replica) of an old Viking longship that was built in Haugesund, Norway, and launched in 2012.

In May next year she will set out on a voyage from Norway to Newfoundland via Iceland and Greenland, and the project organizers have just announced they are accepting applications for volunteer crew.

You need at least two months of free time to do it and presumably should have some sort of useful skill to boost your chances of being selected.

Conditions aboard look to be very Spartan by modern standards, with no shelter except for a tent on deck, but by traditional Viking standards it should be a veritable luxury cruise.”

Read more: Calling all Vikings. More sailboat news.

What Can Be Learnt From a 17th Century Town

wattle and daub wall“In Plymouth, Massachusetts — the site of the first English colony in America — Matteo Brault spends his days living a 17th century life, along with dozens of other re-enactors on the modern-day Plimoth Plantation. Brault works full-time as a 17th-century style blacksmith, using traditional tools like a grindstone, hand-made nails and a large bellows for making the fire hot enough for forging iron and steel. He also helps build the traditional shelters.”

“The simplest homes in town were built using cratchets — natural forks in trees — as support for the ridgepole of the roof. The walls are built up with “wattle” — small sticks for the lattice structure — and “daub” — a mortar of clay, earth and grasses. Instead of using the traditional English lime wash to protect the walls, the colonists took advantage of the plentiful wood in the America and created clapboard siding by cleaving wood into thin boards. For the thatch roofs, large bundles of water reed or wheat straw are woven with a giant needle by two people working in tandem (one outside and one inside). “It’s like a giant quilt made of grass,” explains Brault, “which makes a water-tight roof that essentially acts as a giant sponge. It absorbs water and laps it off.”

Watch the video. Picture: a wattle and daub wall in Germany.

Photographs of American Indians

photographs of american indians

First People” hosts a large and wonderful collection of American Indian photographs online, dating from the late nineteenth and early twentieth century. Aside from the portraits (which include, among others, the Edward S. Curtis archives), there are picture galleries of tepees, boats, pottery and basketry.

Previously: Walter McClintock’s glass lantern slide collection of the Blackfoot Indians. [Read more…]

Change Ringing

Despite the curtailing of their liturgical uses, at the beginning of the seventeenth century a lot of church bells remained hanging in church towers. Ringing them was an activity pursued with great enthusiasm, often by groups of boozy young men. Paul Hentzner, a German lawyer who traveled through England in the final years of the sixteenth century, wrote that the English were “vastly fond of great noises that fill the ear, such as the firing of cannon, drums, and the ringing of bells, so that it is common for a number of them, that have got a glass in their heads, to go up into some belfry, and ring the bells for hours together for the sake of exercise.”

It was in these long, beer-fuelled ringing sessions that change ringing was invented, as a codification of the disorganized ringing that Hentzner describes. It seems to have started in London and southeast England in the early seventeenth century; it spread, and by the 1660s was a fashionable recreation, with societies springing up all over south, central, and eastern England to further the practice.

St Mary-le-Tower Bellringers

[Read more…]

Precolumbian Causeways and Canals

precolombian causeways

Detail of an engineered landscape in the Bolivian Amazon. Artwork by Clark Erickson.

“In contrast to the Western obsession to drain what are considered marginal wetlands for agriculture, farmers in the Bolivian Amazon may have intentionally expanded wetlands and wetland productivity through earthwork construction, which impedes, rather than enhances, drainage. The precolumbian farmers did not use causeways as dikes to prevent inundation of fields and settlements, but rather to expand and enhance inundation for agricultural production. At the same time, impounding water with well-placed causeways and the creation of canals improved and extended the season of transportation by canoe across the landscape. The grid-like structure also permanently marked land tenure in a highly visible manner.” [Read more…]

Crimean Ovens

“Starting in 1861, the wintertime Union field tent hospitals of the U.S. Civil War often used subterranean heating systems known as Crimean Ovens. The system under discussion was basically a firebox, or oven, on the outside of the tent, with a shallow, brick-lined, sheet-metal-covered trough running down the center of the tent’s interior, and ending in a chimney on the opposite exterior side of the tent. The tents were placed on ground with slight inclines, allowing the hot air to naturally rise and escape out the flue.”

crimean oven

“Dr. Charles Tripler, Surgeon and Medical Director of the Army of the Potomac, writes in a letter of November 1861 the following description of “a modification of the Crimean Oven”, devised and put into operation by Surgeon McRuer, the surgeon of General Sedgewick’s Eighth Brigade:

A trench 1 foot wide and 20 inches deep to be dug through the center and length of each tent, to be continued for 3 or 4 feet farther, terminating at one end in a covered oven fire-place and at the other in a chimney. By this arrangement the fire-place and chimney are both on the outside of the tent; the fire-place is made about 2 feet wide and arching; its area gradually lessening until it terminates in a throat at the commencement of the straight trench. This part is covered with brick or stone, laid in mortar or cement; the long trench to be covered with sheet-iron in the same manner. The opposite end to the fire-place terminates in a chimney 6 or 8 feet high; the front of the fire-place to be fitted with a tight movable sheet-iron cover, in which an opening is to be made, with a sliding cover to act as a blower.

crimean oven 2By this contrivance a perfect draught may be obtained, and use more cold air admitted within the furnace than just sufficient to consume the wood and generate the amount of heat required, which not only radiates from the exposed surface of the iron plates, but is conducted throughout the ground floor of the tent so as to keep it both warm and dry, making a board floor entirely unnecessary, thereby avoiding the dampness and filth, which unavoidably accumulates in such places.

All noise, smoke, and dust, attendant upon building the fires within the tent are avoided; there are no currents of cold air, and the heat is so equally diffused, that no difference can be perceived between the temperature of each end or side of the tent.”

Read more: 1 / 2 / 3.

Low-Tech Kite-Fishing in the Indo-Pacific

kite fishing 1908

“We set out to sea but kept close to the canoe occupied by the two fishermen. Off the island the old fisherman gradually played out the kite. As it swung in the breeze we noticed that the webbing just had enough length so that it touched the surface of the sea with every soft fall of the canoe as it rose and dipped. Presently there was an agitation in the sea behind the canoe and we could see several fish coming to the surface. Apparently intrigued by the tantalizing touching of the surface by the webbing, the fish were jumping for it. Finally one caught the webbing in his mounth and with a shout, the old fisherman neatly hooked it in with a hand net.”

Picture: Kite-Fishing off Pitilu (Admiralty Islands) as photographed in 1908 by H. Vogel of the Hamburg Südsee Expedition.

[Read more…]

Abandoned Flour Mill in Spain

Abandoned factories in spainLugares Abandonados is a fascinating blog documenting abandoned buildings in Spain.

There are quite some photo reportages about factories, and this one in particular is noteworthy: a forgotten flour mill with part of the machinery still in excellent condition.

The author does not reveal any location for any of the buildings on the blog.

 

An Engineering Exploration of Stonehenge

An Engineering Exploration of Stonehenge

The Britons worked out how the heavens move thousands of years before the Greeks started thinking about it. That is, in a nutshell, the story of engineer and author  Jonathan Morris.

His hypothesis originated from a solar renewable energy concentration system which he developed, using small fixed pieces of flat reflectors.

By chance, he discovered that the structural support of the solar energy system appears to be duplicated at Stonehenge, the enigmatic monument built 4,000 to 5,000 years ago. Every single one of the technical features required are precisely duplicated in size, height, location and orientation at Stonehenge.

Morris outlines his ideas in a novel (“The Broken Stone”) and a technical outline, available via his website: “Heavens’ Henge: A geocentric worldview“.