Get flash to fully experience Pearltrees
Inlet-outlet cover of a valve for a nuclear power station produced using investment casting
Maiden Castle in England is one of the largest hill forts in Europe. [ 1 ] [ 2 ] Photograph taken in 1935 by Major George Allen (1891–1940).
A pictogram , also called a pictogramme or pictograph , [ 1 ] is an ideogram that conveys its meaning through its pictorial resemblance to a physical object. Pictographs are often used in writing and graphic systems in which the characters are to a considerable extent pictorial in appearance.
Diffusion of metallurgy in Europe and Asia Minor . The darkest areas are the oldest.