Category Field Guide to Appropriate Technology


When a female duck tries to hide or sits on a nest more often, she is probably ready to set. Make her a setting nest in a quiet, dark place well sheltered from rain, sun, and wind. The nest can be a simple hole in the ground or a box lined with clean, dry grass or straw. A female duck can cover 10 to 12 eggs, so try to collect this many eggs from your flock. However, when you collect the eggs, handle them very carefully. If you shake eggs too much, they may not hatch. Eggs that are very small or very large may not hatch—choose medium-sized eggs. Eggs to be used for setting should be no more than ten days old. The eggs should be clean. If they are dirty, clean them with a soft, damp cloth...

Read More


Based on Better Farming Series 12. Raising Sheep and Goats,

A. J. Henderson: Food and Agriculture Organization of the United Nations, Rome, 1977,

ISBN 92-5-100152-9


The traditional way of breeding sheep and goats does not take much work, but it also does not produce much. It takes little work because the animals are not looked after. They are not fed, they are not given water to drink, and they are not given any shelter. This method of breeding, however, produces little. The animals are small, they are often ill, and their young ones often die. If a farmer breeds sheep and goats in the modern way, he or she can earn more money.

A few terms should be defined: A flock of sheep consists of 1 male, called the ram; 20 females, called ewes; and young ones call...

Read More


Gwinyai Dziwa

In the context of social development, indigenous traditional health practitioners across the African continent play a significant role in health care education, community leadership, and provision of preventive and curative remedies. Traditional health practitioners are well known for their advocacy for environmental protection. Their approach to health poses little environmental degradation, since they obtain their herbs and wait for the bushes to regenerate. Lately, they have been recruiting local communities in reforestation programs.

Traditional health practitioners come in the form of spirit mediums, herbalists, and birth attendants. The spirit mediums treat psychosomatic illnesses and play a significant role in helping families with victims of mental illness...

Read More


World Health Organization, Regional office for South-East Asia New Delhi, India 1996)

At some point in the disease process of AIDS, there is nothing more that can be done to effectively treat the opportunistic infections or completely relieve the symptoms that they cause. The infections or illnesses have progressed beyond what medicines can cure. At this point, the goal of all care (medical, nursing, religious, and psychological) is to keep the person as comfortable as possible and to maintain his or her dignity. In some places this is called palliative care.


It is often difficult to decide when the focus on medical treatment should stop and care for the dying should begin. The change in care may begin, for example, with the following.

• When medical treatment is...

Read More


The rounded shapes, especially of cupolas, can result in a significant degree of reverberation that is an asset or a disadvantage depending on the intended use of the space. Simple measures, such as corbelled elements or suspended cloth, can be used to reduce reverberation.


To ensure stability, the form should be as close as possible to the line of force. In the case of vaults, for evenly distributed loads, the best form resembles that of an inverted suspended chain

(catenary). This applies both to flatter and to slender forms. See Figure 9.

ACOUSTICSArches, vaults and cupolas are heavy roof­ing elements and they exert thrusts that increase with the degree of flatness, the span and the weight of the structure. These thrusts may be concentrated or dispersed...

Read More


First a papyrus mat is placed on top of the purlins; then a layer of black polyethene and another one or two papyrus mats complete the roof. These materials are fixed to the purlins with nails and iron wire. Nails are fixed to the purlin at 15 cm to 20 cm spacing, and the iron wire is then stretched over the top of the papyrus mat and secured to the nails. The papyrus has a life span of about three years, but that can be extended by treating the papyrus with a water-repellent paint.


Otto Ruskulis IT Technical Enquiries Service (Based on ATBrief No 19 "Gypsum Processing and Use" Appropriate Technology, Vol. 23, No. 4)

Gypsum plaster is a very useful building material that can be produced with simple processing equipment. It is made from deposits of gypsum rock or sand...

Read More


Oxen are not appropriate for all farmers. Potential users of oxen must understand the animal’s limitations. Cattle require feed, water, security from theft and large predators, and shelter from extremes in the weather. The investment in an ox is a substantial investment for poor farmers. To lose an animal to disease or theft is a tremendous financial loss. Many farmers prefer hand labor rather than risking what little resources they have on a technology they do not understand. If the animals are employed just for plowing and planting and greater acreage is planted, there may be a severe labor bottleneck during weeding...

Read More

Beam Bridge

The beam bridge uses one or more beams crossing the river or obstacle. (A fallen tree across a stream is an example). Wooden beam bridges can cover spans up to 15 meters, concrete made from a flat slab up to 10 meters, concrete made with a beam on the undersurface up to 15 meters, and steel up to 25 meters. Construction is not difficult. Material—wood, concrete and reinforcing steel for concrete bridges, or structural steel—should be chosen appropriately. Beam bridges are usually the least costly for spans less than 12 meters.

A top view of a wooden beam bridges is shown in Figure 30. The dotted horizontal lines represent long wooden beams under the ropeway. The beams should be placed about 1 meter apart. The beams themselves are approximately.5 meter deep and .1 meter thick...

Read More