Amaranth to Zai Holes, Ideas for Growing Food under Difficult Conditions (ECHO, 1996, 397 p.) 13: Energy and technologies (introduction...) Organizations and resources Technologies

Amaranth to Zai Holes, Ideas for Growing Food under Difficult Conditions (ECHO, 1996, 397 p.)

13: Energy and technologies

Appropriate technologies can reduce tiresome labor and increase the efficiency of the rural family in their work at home and in the fields. There are many simple machines, tools, utensils, pumps, and other items which can make significant improvements in people's lives, but not all are suitable for the living situation. Development workers must be particularly cautious with introducing and promoting new technologies too hastily. It is essential to determine the needs and commitment of the community toward new methods.

There are many excellent organizations and resources with counsel and publications on energy systems, labor-saving devices, construction, and other areas. ECHO does not specialize in appropriate technologies, and people who send us technical questions on these areas are usually referred to the organizations listed here for specialist assistance.

Organizations and resources

APPROPRIATE TECHNOLOGY MICROFICHE LIBRARY. This "library that fits in a shoebox" is one of the most comprehensive resources we have seen! The Library includes the complete text of 1000 of the best books (138,000 pages) on village-level A.T. and sustainable development. It includes many out-of-print materials, classic field resources like Where There Is No Doctor and the VITA Village Technology Handbook, and extensive sections on agriculture, animal husbandry, health, construction, water systems, and small industries. At $895 it costs about 5% of a similar paper library. This would be a great resource on the field; perhaps you can ask your supporters to sponsor this as a project. The Library includes a copy of the Appropriate Technology Sourcebook, which gives a careful review of every book in the Library. You may order the Sourcebook separately for $23.95 paperback/$29.95 hardcover. (This 800-page annotated guide to appropriate technology literature includes reviews of 1150 of the best books on "village technology" from around the world. The purpose is not to give enough information to get to work, but books and plans are reviewed in sufficient detail to help you decide whether to purchase them. Ordering information is given for each book.) They plan to release this on CD-ROM in mid- 1996. Three microfiche readers are also available, for $250 (office use), $375 (briefcase style), and $625 (prints from the screen). Contact the Appropriate Technology Institute, W110 Engineering Research Center, Colorado State University, Fort Collins, CO 80523, USA; phone 800/648-8043 or 970/491-7189; fax 970/491-2729.

VOLUNTEERS IN TECHNICAL ASSISTANCE (VITA) has an information service which provides technical help to people working in the developing world. Most of you have probably written to VITA from time to time with questions or requests for plans for appropriate technology items. Their publications on a wide variety of topics are clearly written and the plans are easy to follow. Ask them about their free services in support of development workers. For general information and technical service, write to 1600 Wilson Blvd., Suite 500, Arlington, VA 22209; phone 703/276-1800; fax 703/243-1865. Address publications orders and inquiries to P.O. Box 605, Herndon, VA 22070, USA.

INTERMEDIATE TECHNOLOGY'S TECHNICAL ENQUIRY UNIT can answer specific, detailed questions on a wide range of technical matters, offering information, referrals, and advisory services. They are an excellent contact if you are seeking some particular equipment. Direct your questions to Technical Enquiry Unit at ITDG, Myson House, Railway Terrace, Rugby CV21 3HT, UK; fax +44 -1788 540270; e-mail itdg@gn.apc.org. IT also has country offices in Sri Lanka, Zimbabwe, Bangladesh, Peru, Kenya, and Sudan.

FAKT ASSOCIATION FOR APPROPRIATE TECHNOLOGY can answer questions about technological problems. There is no charge for this service. FAKT consultants assist other organizations in finding socially and environmentally compatible solutions to challenges. They also identify and promote local consultancy structures in-country. FAKT can serve as a resource on the technologies of mini-hydropower, renewable energies, water supply and sanitation, food science/technology, and hospital technology. Their consultancy (with fees) includes planning technical projects, participatory project management, vocational training and craft promotion, evaluations and studies, and training programs and seminars. Contact FAKT Association for Appropriate Technology, Gansheidestr. 43, D-70184 Stuttgart, GERMANY; phone (0711) 21095-0; fax (0711) 21095-55.

SIFAT (Servants In Faith And Technology/Southern Institute For Appropriate Technology) offers practicums in appropriate technologies in Alabama and a few sites in South America. When people contact ECHO who want further training or information on technologies designed for developing countries, we often refer them to SIFAT. They have year-long internships, short courses, Learn & Serve teams, and cross-cultural seminars for short-term mission. Eight-week sessions include principles of community development, cross-cultural communication, and appropriate technologies for basic human needs (1996 cost: US$1200, or $150/week, including room, tuition, food, building materials, and books). Students learn water management, sustainable agriculture, alternate energy, and health and sanitation. Special hands-on projects are arranged depending on the interests of the student.

Write for a brochure. SIFAT will consider requests for financial aid to cover tuition, room, and board while at SIFAT, though these arrangements must always be made well before you leave home. In no case will they cover travel expenses. The government will not grant education visas to attend SIFAT because they are not a degree- granting institution, so citizens from other countries should apply for a tourist visa. They are located on a 180- acre farm approximately halfway between Atlanta, Georgia, and Birmingham, Alabama. Rt. 1 Box D-14, Lineville, AL 36266 USA; phone 205/396-2015; fax 205/396-2501.

THE APPROPRIATE TECHNOLOGY INSTITUTE: see information in Chapter 11 on Human Health (p.283).

APPROPRIATE TECHNOLOGY MAGAZINE FROM IT PUBLICATIONS is an excellent resource on a wide variety of AT topics. Each issue features some topic in depth and includes many case studies and practical ideas from around the world. This quarterly publication is £15/$28 for private individuals via surface mail; airmail postage is £6/$12 additional. You may write for a free index, and many back issues are still available. Write IT Publications, 103-105 Southampton Row, London WC1B 4HH, UK.

AN APPROPRIATE TECHNOLOGY NEWSLETTER. Rus Alit (inventor of the Rus pump; see below) has started an Appropriate Technology Newsletter. We asked how to subscribe. "The receiver will be asked to subscribe after the first three issues. We will give free issues [Ed: write to Rus, not to ECHO] to those who are contributing articles. It will be a quarterly newsletter, costing US$10 per year. Each issue will focus on one particular innovation and will include case study, implications of change, technical details, reference to other AT innovations, and resources available in World Vision Australia department." Write Rus Alit, 7 Bonython St, Rochedale Queensland 4123, Brisbane, AUSTRALIA; phone/fax (07) 341-2371.

MENNONITE HARDWARE STORE IS UNIQUE. When we parked in front of Lehman's Hardware store in Kidron, Ohio, we had to pick a spot between the horse-drawn carriages common in this Amish/Mennonite community. Reflecting the local tradition of continuing with older ways, Lehman's sells items I have not seen in any other store. There were several makes of wood-burning cookstoves, which I had not seen since I was a small child, complete with all kinds of accessories. I saw washboards, hand-powered washing machines, all types of wood working tools, kerosene, gas and gasoline lamps and accessories, sausage stuffers, bottle cappers, fruit peelers and pitters, large copper kettles, many kinds of cast iron cookware, hand-operated grain mills, many types of wood-heating stoves, a gas or kerosene refrigerator and a gas freezer, hydraulic rams and other hand pumps, cream separators, home pasteurizers, etc.

Mr. Lehman took a ten-year leave of absence to serve as a missionary with the Mennonite Central Committee in Zaire. "Soon after my return we decided to print a mail order catalog.... Partly in recognition of the loyal, volume buying of the larger missions and partly as our small contribution to the efforts of missionaries we developed special discounted prices on many of the items commonly used in the 'bush'." They will send the $2 catalog free if you write on letterhead of your mission board. HOWEVER, if you want it sent airmail please send $3 for postage. If you are a missionary, it is IMPORTANT to also ask for the special missionary "non-electric" price list. To call for quotes or advice on replacement parts, phone 216/857-5757. Write to Lehman's, One Lehman Circle, P.O. Box 41, Kidron, OH 44636-0041, USA.

CECOCO "GUIDE BOOK FOR RURAL COTTAGE AND SMALL & MEDIUM SCALE INDUSTRIES AND PADDY RICE CULTIVATION" is a catalog of a great variety of agricultural, food processing, and small industry equipment (for making ropes, looms, paper bags and boxes, wire, bamboo products, and more). It is very unique with products that are difficult to find elsewhere. Send a description of the equipment you are looking for or ask for a list of products from CECOCO, P.O. Box 8, Ibaraki City, Osaka 567, JAPAN.

INFORMATION AND ADVICE AVAILABLE ON BUILDING IN THE TROPICS. When Dr. Reuben Sperling visited with us to discuss structural aspects of roof top gardens, he mentioned that he used to work with the overseas division of the Building Research Establishment in England. After seeing the practical literature they have published I am convinced that many of our readers should know about this group. I quote from their literature:

"One of the Division's most important publications is the series of Overseas Building Notes, distributed to readers in over 80 countries. The Notes are published approximately six times a year and recent titles have included 'Preservation of timber for tropical buildings', Stabilized soil blocks for building', Roofs in hot dry climates' and 'The management of resources on construction sites.'" Many papers are written by experts from third world institutions. "Several hundred inquiries are answered each year. Similarly many research workers, builders, architects, housing managers and students from all over the world visit the Division each year ... [to discuss] building research or building techniques in use elsewhere."

I have copies of some of their publications. Although this is far removed from my expertise, they seem to be very practical and understandable. You can obtain copies for a small charge (or perhaps free if you explain what you are doing). Here are some selected titles: Small buildings in earthquake areas; Termites and tropical building; Brickmaking in developing countries; Health aspects of latrine construction; Timber in tropical building; Bitumen coverings for flat roofs; Low cost housing in urban and peri-urban areas; Rice husk ash cement; Building for comfort; and Disease reduction by improved house construction. Address your requests to BRE Bookshop, Building Research Establishment, Garston, Watford, WD2 7JR, UK.

ENGINEERING MINISTRIES INTERNATIONAL (EMI) PROVIDES FREE HELP TO CHRISTIAN MINISTRIES. Engineering Ministries International (EMI) is a group of evangelical professional architects and engineers who volunteer their services "to proclaim the love of Jesus Christ through the work of Christian relief projects." They have experience in such fields as structural engineering, architectural planning, hydraulics (including hydrogeology and water supply), electrical and mechanical engineering, and surveying. EMI's Director, Michael Orsillo, has years of education and experience in civil engineering, and he is also an ordained minister.

Many mission buildings and churches are built with little or no professional design work. EMI is able to provide competent design assistance at a fraction of the cost of professional consulting services. Often the cost of assistance is off-set by a savings in material costs, time over-runs or future maintenance problems. They are presently working with plans for an orphanage in Honduras, a low-budget church in India, a water system for an Ethiopian women's hospital, and a youth camp in Indonesia.

In order to be eligible for this technical assistance from EMI, projects must minister to the needs of the poor, directly proclaim the gospel of Christ, and have realistic possibilities for funding the building of the project once the design is completed. EMI's design services are provided free of charge. They do not fund the cost of construction. For more information, contact Mr. Michael Orsillo, Engineering Ministries International, 110 S. Weber, Suite 104, Colorado Springs, CO 80903, USA; phone 719/633-2078; fax 719/633-2970.

MICRO-HYDROPOWER SOURCEBOOK. This book deals with a topic beyond my expertise. However, I can tell that it would be "must reading" if I were trying to decide whether to begin a project to harness waterpower, and even more so if I decided to go ahead with the project! ("Micro-hydropower" refers to plants that generate less than 100 kilowatts of electricity.)

This 285-page book is exceptionally well-illustrated with 200 photos of case examples of facilities in the third world and about as many drawings. It has a variety of designs, approaches and case studies. It provides the theory as well as practical guidelines required to plan, design, and implement micro-hydropower schemes. Chapter topics include measuring head and discharge, streamflow, site selection and layout, construction of the facility, turbines, electrical vs. mechanical power, governing, electrical aspects, and case studies.

I wrote the author, Allen Inversin, asking whether most of our readers would not find electrical generation more technical than they could handle. He replied, "I should note that the Sourcebook focuses not only on electricity generation, but possibly more importantly on the generation of mechanical power to directly drive agro-processing equipment. As it turns out, the most successful microhydropower projects are those which provide mechanical power to mill grain, hull rice and expel oil from oil seed. The success of such programs in Nepal is due wholly to the fact that the focus ... is on productive, income-generating end uses. ...the generation of electricity is a secondary benefit, which is generally realized only after the plants have already generated the income to cover their costs."

The books may not be available after mid-1996. The cost is $22 plus shipping. Individuals working in a volunteer capacity overseas qualify for a special price of $18 plus shipping. Shipping costs $6 for surface mail. For airmail add $10 in Latin America, $15 in Europe and Africa and $20 in Asia. Order from NRECA International Foundation; Attn: Sourcebook; 1800 Massachusetts Avenue, N.W.; Washington, D. C. 20036-1883; USA; phone 202/857-9622; e-mail 74720.551@compuserve.com.

In response to this review in EDN, John and Caryl Busman wrote of their experience in Tamil Nadu State in southern India. "Although power was provided erratically and at widely varying voltages, farmers did everything possible to connect their irrigation pumps to the 'grid.' Attractive electrical rates and low maintenance costs compared to bullocks or diesel made the decision to switch an easy one. That one state ended up with a million electric pumps on small irrigation wells.

"The question is, Who fixes things when they break? The informal sharing of knowledge has created a whole new group of technicians. Little villages would have 4-5 people who knew the business of rewinding motors. You would see motors hauled to town on ox carts for service, with quick turn around time for repair. What is most interesting is that this has all happened within 20 years."

HYDRONET is an international newsletter for the dissemination of information on micro-hydro power techniques and experiences. It is published in English, Spanish, and Indonesian three times a year. Contact Intermediate Technology, 15B Alfred Place, Colombo 3, SRI LANKA; phone 577455/6/7; fax 577458; e-mail itsrilan@sri.lanka.net.

NEW DESIGNS FOR RURAL ELECTRIFICATION (80 pp.) describes the technical and organizational innovations which enabled a power company in Nepal to reduce costs and maximize benefits of supplying electricity to rural subsistence communities. Topics such as the cost of grid extension, utility poles which can be easily carried to remote areas, housewiring alternatives, low-wattage electric cookers, users' organizations to coordinate the villagers and the electric utility company, and community motivators are included. Many pictures are included. Cost is $20 including airmail postage. Order from NRECA International Foundation, Attn: New Designs for RE, 1800 Massachusetts Avenue, N.W., Washington, D.C. 20036-1883, USA; phone 202/857-9622; e-mail 74720.551@compuserve.com.

MAKING WHEELS: A TECHNICAL MANUAL ON WHEEL MANUFACTURE (153 pp.) is a well-illustrated and detailed book on this low-cost technology based on a hand-operated bending device. Rims can be made for bicycles, carts, and cars. An assembly jig ensures that wheels are constructed to a consistent high quality. Readers should have good metal-working skills. Available for $28.95 plus postage from Women, Ink., 777 UN Plaza, New York, NY 10017, USA; phone 212/687-8633; fax 212/661-2704; or £14.95 from Intermediate Technology Publications, 103/105 Southampton Row, London WC1B 4HH, UK; fax 44 171 436 2013; e-mail itpubs@gn.apc.org. Ask for their catalog and a list of distributors in developing countries.

Technologies

"HOW TO MAKE A ROPE AND WASHER PUMP." Robert Lambert wrote this 32-page booklet for the Intermediate Technology Development Group. The manual shows how to make a simple, cheap pump suitable for smallholding and garden use (see illustration from the book). The pump, which can raise water up to 6 meters (18 feet) from a stream, pond or well, has been field-tested in Tanzania and Zimbabwe. An output of 1 liter per second at 5 meters can be sustained, enough to irrigate 1/4 hectare if pumped 20 hours a week.

It is designed especially for irrigation of small plots. Providing "supplementary irrigation to crops at critical periods of growth can greatly increase the yield ... [or even] make the difference between a good crop and total failure." It is "particularly valuable for vegetable production in the dry season when vegetables may be grown only through the use of irrigation. [And prices received will be higher.]"

rope and washer pump

"The rope and washer pump is ... capable of lifting relatively large volumes of water from a water hole or well to its own height [but no higher]." "A rope is pulled up through a pipe by means of a pulley wheel [an old tire]. Fixed to the rope are flexible rubber washers [cut from a tire] whose diameter is slightly less than the internal diameter of the pipe." As the washers are pulled up through the pipe "water is drawn up and discharged at the top. The rope and washers pass around the pulley wheel and return to the bottom of the pipe."

Every moving part is out in the open and can be hand made with simple tools. The cost of materials in Zimbabwe in 1989 was US$30. A video tape is also available. I cannot review the one I purchased because I forgot that England uses a different video system than we do. However, the booklet is so profusely and well illustrated that I see little need for a video. Order from Intermediate Technology Publications, 103/105 Southampton Row, London WC1B 4HH, UK; fax 44 171 436 2013; e-mail itpubs@gn.apc.org. The price is £5.95 (about $11.50) plus 20% surface postage, 40% airmail. In the USA, order IT Publications from Women, Ink., 777 UN Plaza, New York, NY 10017. They also have distributors in 15 other countries; write or e-mail for one of their excellent catalogs or addresses of local sources near you.

THE RUS PUMP.

Rus pump design

Wayne DeYoung in Haiti writes about a pump that he is sure will interest our network. It was used in a water well project by Dan Cook and others in Haiti. Wayne believes that it has phenomenal value for many gardening situations along rivers or ponds or where a hand dug well is available. "Dan is doing a gardening project where water is the main limitation. They dug a 45 foot deep well at 50ø a foot, only to find that pumps were outrageously priced, especially now with the United Nations embargo. Then he heard that the Reeves in Gonaive had made a pump from PVC pipe. He bought about 50 feet each of 1¼ and 3/4 inch pipe for US $50." Wayne then describes how homemade foot valves were attached to the bottom of each string of pipe and the 3/4 inch string fitted inside the larger one. [Ed: A "string of pipe" refers to a series of pieces of pipe connected to make a long section.] "By pumping the 3/4 inch pipe up and down it pumps water beautifully, at least 5 gallon a minute."

World Vision Australia forwarded a package of brochures for our review (see below to order). The brochures were "developed by our appropriate technologist, Rus Alit, who has traveled extensively introducing the technologies to developing countries." When I saw the size of the brochures I wondered how enough could be included to be useful-each is a single 8½ x 11-inch sheet of paper. But they are clever, to-the-point, and very well illustrated. The brochure on the Rus pump describes how it "has gained wide acceptance in South East Asia and the Pacific because it works well, is cheap and is easy to build." The main components are PVC pipes, a piece of hard wood and a tiny scrap cut from a discarded tire. It can pull water from a well up to 6 meters (18 feet). [The rope and washer pump mentioned above is also made from readily available materials. The model we recently built at ECHO quickly became a hit on our educational tours. It is especially useful for higher volume irrigation where water is pumped a modest height, e.g. up the bank of a stream into the field. It would not work in a narrow tube well.]

Our own appreciation for the Rus pump was heightened when Merrill Esch, who was studying at ECHO in preparation for work in Honduras, built a Rus pump for ECHO from the Australian design. It is unbelievably simple to build. The only part that might be difficult for some would be making the hardwood valve. Merrill even simplified that by using a 2-inch long piece of bamboo. Note that if the inside pipe is extra long, water can be lifted quite a distance. The bottom section of the Rus pump lifts water by suction, perhaps 6 meters (18 feet), then pushes it the rest of the way.

Diagram: Design for the Rus pump, courtesy of World Vision Australia and Rus Alit.

Notes from ECHO's experience with the Rus pump built by Merrill: (1) Selecting a piece of bamboo of the appropriate diameter is easier than making a hollow hardwood cylinder. (2) Rubber flaps made from innertubes are not thick enough. Cut them from tires as the bulletin says. (3) PVC pipe often comes with one end enlarged so that the next piece will fit into it. Merrill found that using this enlarged end for the upper valve made just the right fit inside the larger pipe. He just forced the bamboo into the end and did not need to make any special fittings. Note, however, that we have not used the pump under field conditions.

The complete series of 14 brochures (Rus Pump, Making a Hydraulic Ram, Digging a Tube Well, Making Ferro Cement Water Tanks, Making a Water Filter, Water Sealed Toilet, Stoves, A-Frame, Mud Bricks, and others) is available from to World Vision of Australia for A$10.50 (about US$8) plus about A$5 postage. If you work with any technologies, it is well worth having the whole set. Videos are also available; ask for ordering information. Write Bookstore, World Vision Australia, G.P.O. Box 399C, Melbourne, Vic 3001, AUSTRALIA; phone (03) 287-2233; fax (03) 287-2427. Contact World Vision in your country for more information on the technologies.

THE ROWER PUMP, WEST AFRICAN VERSION. Timothy Volk with the Mennonite Central Committee in Nigeria was prompted by the note on the Rus pump to write about the rower pump that MCC is successfully introducing in Nigeria. "The rower pump is rapidly gaining acceptance here, especially for dry season gardening. The [1994] price for the pump is 500 Naira (US$12.50), compared to 10,000 Naira for a gas powered pump."

The name "rower" comes from its mode of operation. A person sits on a log and "rows" back and forth to pump the water. "It is feasible to pump 60 liters per minute over long periods of time." Water can be lifted up to 6 meters.

The rower pump concept was developed in Bangladesh, where they are today mass-produced and used primarily in irrigation. The West African version made design changes to lower its cost and simplify its construction. For example, in the Bengali version the piston and foot valve are made from machined aluminum and injection-molded polyethylene, while the corresponding parts in the West African pump are handmade from PVC plastic.

a Rower pump

A detailed and well-written 36-page book, MCC West African Rower Pump, is published by the Africa desk of the MCC. They donated a few copies for ECHO to distribute to interested members of our network. If you want it sent via airmail enclose postage ($2 in the Americas, $4 elsewhere). The rower pump appears to be more difficult to make than the Rus pump, but not too much of a challenge for a mechanically-oriented person. In return for the extra work, the advantage is a higher volume of water and less effort.

HOMEMADE WATER REPELLENT FOR WOOD. Don Bernd wrote to ask what we would recommend to counter molding of "leather, books, accordion, and wood furniture" in extreme humidity in his part of Colombia. The U.S. Forest Service bulletin, "Wood Finishing: Water Repellents and Water-Repellent Preservatives," describes a method for treating wood that is exposed to weathering (but above ground). It is not clear from the publication what effect it would have on indoor wood exposed to extreme humidity, but it is worth a try. They treated experimental wood window sash and frames with the preservative whose formula is detailed below. The window units are in good condition after 20 years' exposure even though all the original paint has weathered away. Untreated painted window units decayed severely and fell off the test fence after only 6 years' exposure.

Extreme caution should be exercised in preparing the water repellent because the organic materials, especially the hot paraffin, are quite flammable. It is best to prepare it outside. Do not use a direct flame or heat near a flame such as the pilot light on a stove. To make one gallon of repellent, melt 1 oz. of paraffin wax in the top unit of a double boiler. Pour this into enough solvent to make a final volume of one gallon, stirring vigorously. The solvent should be at room temperature and can be either turpentine, mineral spirits or paint thinner. After these two are mixed, add 1.5 cups of boiled linseed oil. Exterior-grade varnish can be used in place of boiled linseed oil, but twice the volume (three cups) should be used. The preservative can be applied by brushing or dipping. The wood can be painted after it is dried if desired.

Even more protection can be obtained by including 1.75 cups of pentachlorophenol concentrate 10:1 (40%). The solution is then called a water-repellent preservative. Because this substance is poisonous it should be limited to outside use. Remember that it may be toxic to animals and plants. For (a little) additional information and a good list of product suppliers, request the free publication FPL-0124 from Information Services, U.S. Department of Agriculture, Forest Products Laboratory, Forest Service, 1 Gifford Pinchot Dr., Madison, WI 53705-2398, USA; fax 608/231-9592. (They offer their recent publications on wood utilization research to provide technical information on wood processing, timber economics, tropical woods, wood protection, and related topics.)

PRESERVING WOODEN BEE HIVES It is possible that the water repellent just described would be especially helpful for treating wood that is to be used in constructing bee hives. But be careful if you add toxic chemicals to turn it into a water-repellent preservative. Professor G.F. Townsend at the University of Guelph in Ontario, Canada wrote the following: "In tropical countries it is necessary to either use wood that is resistant to termites and ants, or to treat the wooden parts of the hive. If you wish to stay away from any of the wood preservatives, the equipment may be dipped in a very hot solution of paraffin wax (about 158 C) for a two-minute period. Sometimes up to 50% rosin or some beeswax may be added to this mixture. This procedure is dangerous unless special equipment is devised for the dipping and heating. The only wood preservative which is relatively non- toxic to bees is copper naphthanate. ...If only paint is used, it should be an oil-base paint containing aluminum."

"WICK" SUGGESTED TO PRESERVE UNTREATED POLES. (Taken from Living Off the Land, April 1982.) Joy Horton in Loja, Ecuador wraps posts and poles to several inches above the expected ground level with burlap or newspaper soaked with a mixture of used motor oil and creosote. The wrapped post is then placed in a hole and more of the mixture poured onto the wick. Further treatments are applied twice yearly to the part of the wick that remains above ground. She does not recommend this method for garden stakes or trellises, as the mixture is toxic to plants. (Each issue of Living Off the Land is a "subtropic newsletter" which features one plant, usually a fruit, including recipes. It is oriented primarily to Florida readers. A one year subscription of 5 issues is $15 overseas airmail from Geraventure Corp., P.O. Box 2131, Melbourne, FL 32902-2131, USA. The editor, Marian Van Atta, also has a number of books available; write for a listing.)

PEDAL-POWERED VEHICLES. Ken Hargesheimer wrote, "There is nothing that costs so little that does so much for a third world family as a bicycle trailer. Mine is a chassis on which various units (e.g. pickup for hauling children, animals, tools or a tanker) can be mounted. It requires no welding. I can send all kinds of information and plans to anyone interested." He also sent us a list of other designers, makers, etc. of pedal-powered vehicles and equipment, including people in many other US states, Canada, Kenya, and India. The products include a bicycle ambulance, weeder/harvesters, mowers, a grain reaper, and more. In the US send a self-addressed stamped envelope and $1 for copies; overseas send two International Postal Reply Coupons. His address is P.O. Box 1901, Lubbock, TX 79408, USA; phone/fax 806/744-8517.

SAWDUST USED TO FILL OLD TRACTOR TIRES. CERES, the magazine of the Food and Agriculture Organization, reported a method for using old puncture-prone tractor tires in making ox carts (September/October 1984 issue). Farmers would not accept metal wheels and could not afford new tires. Engineers settled on using old tires filled with sawdust. They are not susceptible to puncture and provide almost the same ride as air-filled tires. The cart carries 500 kg.

SIMPLE SAWDUST COOKERS. Dale Fritz, a volunteer appropriate technologist who came to ECHO after years of experience in Afghanistan, built some simple stoves to heat our greenhouses with sawdust on a few cold nights this winter. They were modeled after "sawdust cookers" which run on dry sawdust, wood shavings, rice hulls, or similar materials, producing a moderate heat for an extended time.

simple stoves to heat our greenhouses with sawdust

A simple stove can be made from a gallon tin can with the top removed and a 1.5-inch (3.8 cm) hole cut in the middle of the bottom. Insert a metal or PVC pipe or wooden pole vertically in the hole, and add dry sawdust in layers, packing it down firmly before adding more. Fine, highly compressed sawdust burns longer than coarse or loose material. When the can is full, carefully remove the pipe or pole straight out of the sawdust to form a flue. Twist it slowly as you pull to keep from knocking particles loose. Place the can on two bricks which touch on one corner. Air will enter the bottom hole and be drawn up the flue by the flame. Light some paper and put it under the flue to ignite the sawdust. The sawdust will burn from the red-hot central core outward with an almost invisible flame.

Place two metal pieces across the top of the can on which to set the pot, while holding it high enough to maintain a draft for the flame. Dale found that the smoke could be reduced by cutting a 1.5-inch hole in the removed top and replacing it on the stove after packing in the sawdust. To nearly eliminate smoke, cover the outside edges of the top with a small amount of soil or sand. This lid sinks down as the sawdust is consumed.

To make the stove burn longer, increase the stove's diameter. Test stoves at ECHO 6 inches in diameter and 8 inches high (15 and 20 cm) burned for three hours, although toward the end the heat was not intense. A stove 16 inches in diameter and 20 inches high (41 and 51 cm) burned for over 8 hours. To make the stove hotter, use a taller container or join two cans together.

Regulate the rate of burning by opening or closing the base bricks to modify air flow. It is possible to extinguish the stove by cutting off the air flow on the top or bottom and relight the unused sawdust later, although rice hulls continue to smolder and cannot be reused. Other suitable fuels include chaff, coffee bean hulls, straw, or mixes of these materials. With some materials, ash will collapse inward and it may be necessary to gently clean out the bottom vent hole to maintain air flow.

Charlie Forst says that he used these cookers much of his four years in Zaire. "I saw them in use years ago by sawmill cooks in West Virginia. I often cooked breakfast in Zaire using rice hulls or coffee hulls. As long as the material is dry, it can be packed in a few minutes and the fire lit. After breakfast I would put rice or beans on the stove and let it burn out.

"Usually you do not even see smoke, just an almost invisible blue flame. But a gummy black layer does appear on the bottom of your pan. I made my stove about 8 inches (20 cm) diameter and 16 (40 cm) inches high. When visiting in one of the poorer sections of Kinshasa, Zaire, I saw quite a few people using variations on the stove, using waste from casket makers or other carpenters."

It is also possible to construct a similar stove out of bricks, with vertical and horizontal flues. Depending on the pots and other conditions, it may be more fuel-efficient to place the support bars for the pot lower in the stove so the pot can be sunk into the stove, making better use of the heat.

HOW CAN I SIMULATE LONG DAYS TO MAKE PLANTS BLOOM? Many plants respond to the length of days. For example, most winged beans will bloom only when days are short; most onions will only form bulbs when days are long, etc. In some cases (including the above examples) varieties are available that do not have these day-length restrictions. But what can you do when such varieties are not available?

It turns out that what daylength-sensitive plants are actually measuring is the length of the night. For example, a temperate plant that blooms and produces seed when the days are long is actually responding to the short nights of summer. If you live in the tropics where nights are never as short as they are during the summer in temperate regions, you might still be able to get it to produce seed by interrupting the night with a period of artificial light. The plant will respond as though it had experienced two short nights-or one long day!

For another example, suppose you want to make cuttings of a temperate plant that in its native climate grows all summer (short nights) and blooms in the fall (nights about the same as are found all year in the tropics). There is a good chance it will bloom continually in the tropics, which makes it difficult to make cuttings. You can probably make it stop blooming by artificially shortening the nights.

Alan Ferguson in Bangladesh recently wrote us for information on how much darkness or light has to be provided to induce flowering, and how this could be measured without equipment. I passed the letter on to Carl Scharfenberg, a member of ECHO's Board of Directors. Carl is also vice-president for research at Yoder Brothers Nursery, one of the largest commercial nurseries in the States. They make frequent use of techniques for altering day lengths in their business, both artificial darkness when they need long nights and lighting when they need shorter nights.

Carl said the norm is to use 10 foot candles of light for the four hours between 10 P.M. and 2 A.M. A good rule of thumb is that if you divide the total watts of your lights by the area covered you should have 1 watt per square foot. If you use florescent lighting instead of incandescent, the number should be 0.6 watts per square foot.

Here is a neat trick they use to reduce the amount of electricity (which could be even more important if you must generate your own). They have found that they can divide the area into two parts. The lights in one area are left on for 5 minutes, then they are shut off and lights in the other area are left on 5 minutes. This is repeated 5 minutes on and 5 minutes off in each area for the four hours. This works just as well as four continuous hours of illumination, but uses half the electricity.

What about the opposite need: darkness to make longer nights for short day plants? This requires "nights" with less than 1 foot candle of illumination for about 13 hours. Carl uses a rule of thumb that it must be so dark that you cannot read a newspaper. A black polyethylene plastic cover works well.

CASSETTE PLAYER AND RADIO NEED NO BATTERIES. A few of you are in places where batteries are hard to come by and short-lived. We purchased a new cassette-tape player with a built-in generator and crank. By turning the crank at a rather moderate rate, the cassette operates just as though it had batteries. It plays at a uniform rate even if the cranking rate is irregular. It has a fast forward, rewind, and volume control, but does not record. It also runs on 4 flashlight batteries, 110 volts, 220 volts and either 6 or 12 volt car batteries. You must provide the adaptor for use in a car. They are available only to persons in the third world for use in their Christian work. Language Recordings International sells "The Messenger" for US$27 plus postage; contact them at P.O. Box 40181, Pasadena, CA 91114, USA; phone 213/250-0207.

Spore (Feb. 1996) featured the wind-up radio "Freeplay," with 20 seconds of winding producing 40 minutes of listening time. The radio will play for 7,000-20,000 hours. It can be used anywhere to receive VHF-FM, MW- AM, and Short Wave frequencies. Cost: US$35-45 plus shipping. Write Baygen Agency, 6 White Horse Dr., Epsom, Surrey KT18 7LY, UK.

SERRATED HAND HOE. I-Tech (P.O. Box 413, Veneta, OR 97487, USA) is an organization specializing in appropriate technologies. Public disclosures are made of all innovations so that they are in the public domain. They have developed plans for many improved labor-saving devices, including rice and wheat hullers, weeding spades from masonry trowels, a bean thresher using a manual lawn mower, and more. The serrated hand hoe is a useful tool: note the metal blade hand hoe with grooves.

The hoe normally uses a straight edge to cut plant roots and stems. This can be improved by grinding slanted grooves or notches on its cutting edge. The grooves give a serrated edge to the hoe and keep the plant from sliding out of the cutting edge as it is being cut. Grooves are slanted at a slight angle, those on the right side slanting one direction and those on the left in the other.

It also requires less force to hoe with a serrated edge, for two reasons. First, the serrated edge has less surface area for initial contact with the plant. The result is that the entire momentum of the swinging hoe is transferred to a smaller area of the plant, giving a deeper cut. Second, the grooves also tear as well as cut. The tearing action is enhanced by slanting the grooves.

The modification can be done with a hand-held electric grinder in a few minutes. Grooves are approximately 0.8 mm (1/32 inch) deep by 16 mm (5/8 inch) long, spaced 13 mm (1/2 inch) apart. They are ground on the flat side of the hoe that faces the worker. Grooves ground on the flat side of the hoe will not wear out as quickly as those ground on the beveled side facing the earth, away from the worker. Grooves are also retained when the blade is sharpened on the beveled side. As the hoe wears, the sharp edges of the grooves are exposed.