Originally published in 1931, this is the story of the lighter-than-air ship. It is not generally known that the first passenger-carrying flight was made in 1783, more than a century before the Wright brothers - or that flying really began with lighter-than-air craft. Benjamin Franklin was one of the witnesses of these earliest flights and wrote home to friends in America about them.
Originally published in 1931, this is the story of the lighter-than-air ship. It is not generally known that the first passenger-carrying flight was m...
The treadle irrigation pump is able to lift up to seven thousand litres of water per hour using the power of the human body, and can be made locally at low cost in small-scale metalworking shops. Its acceptance in Bangladesh where it was first developed in 1984 is extraordinary, with over 500,000 pumps estimated now to be in use. The current design in this manual has evolved from the Bangladesh original into a fully portable pump with both lift and pressure capacity and is especially good for use in permeable soils where water cannot easily be distributed through channels.
The treadle irrigation pump is able to lift up to seven thousand litres of water per hour using the power of the human body, and can be made locally a...
The jiko, a charcoal-burning stove consisting of a ceramic liner fitted inside a metal case, burns 25 to 40 per cent less charcoal than the traditional stoves on which its design was based. This book provides guidance on its production and promotion.
The jiko, a charcoal-burning stove consisting of a ceramic liner fitted inside a metal case, burns 25 to 40 per cent less charcoal than the traditiona...
