Copper-plate engraving showing a portable folding bridge designed to cros the moat of a city or castle while protecting the soldiers from enemy fire. Illustration from 'Le diverse et artificiose machine' (The various and ingenious machines) by Agostino Ramelli (1531-c 1600) published in Paris in 1588. Ramelli served as an engineer under the Duke of Anjou and later under Henry III of France. The book has many excellently engraved copper-prints and was written in Italian and French. The prints mainly show machines for drawing water, agricultural and military purposes. A few of Ramelli's designs are linked with earlier engineers such as Hero of Alexandria.
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