The common burnt brick is one of man's great inventions. Five thousand years ago bricks were made in many different shapes and sizes but, one by one, the less satisfactory ones were discarded. Now, all over the world, with only a few exceptions, nearly all bricks are roughly the same shape and size - that is about 9 x 4. 5 x 3 inches. This is neither accidental nor coincidence but the result of five thousand years of what we now call R & D - research and development.