A rare heavy original enamel industrial sign from around 1960; This Dutch water gauge hangs in the inner city canals and measures the water level on the NAP scale. The Normal Amsterdam Peil (NAP) is a reference point for height measurements in the Netherlands. It is the average sea level of the North Sea and is used to measure the water height of the canals. This hard to find NAP sign is in a used but solid condition with a great patina according tot its age. All enamel is firmly attached to the heavy duty metal. Provenance: private collection. Dimensions plate: H114 cm x W13 cm Please see the photos for an accurate impression of this lot. The Netherlands’ long-standing battle with water has produced some of the world’s most advanced hydraulic engineering systems. Objects like this enamel water gauge are tangible relics of that history, reflecting the functional design language of mid-20th century Dutch infrastructure. Today, these pieces are highly sought after by collectors of industrial design, maritime heritage, and urban history.