Mr CHONG shows a topographic map of the Hong Kong Island hand-drawn in the 1980’s, saying that the colleagues had to learn hill shading abroad, which was a highly professional mapping skill performed with a pencil.

Mr CHONG shows a topographic map of the Hong Kong Island hand-drawn in the 1980’s, saying that the colleagues had to learn hill shading abroad, which was a highly professional mapping skill performed with a pencil.

Mr CHONG shows a topographic map of the Hong Kong Island hand-drawn in the 1980’s, saying that the colleagues had to learn hill shading abroad, which was a highly professional mapping skill performed with a pencil.