The business series
The trade routes were created after Kôhler had left Nøstetangen and settled as an independent glass engraver in Christiania in
February 1770.
There he could have close contact with his clients, which must have been important in the preparation of the Norwegian business pictures.
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Source: Randi Gaustad Cheers for Norway! : Nøstetangen's exciting pictorial world
Saltworks, Holter series
The engraver HG Kôhler has been interested in showing how the salt extraction took place. He has depicted the degree houses with the basins where the salt water was pumped up from the sea. When the salt concentration had risen in the first sump due to evaporation, the water was passed to the next, where the process was repeated. The grade houses had roofs, but no walls so that sun and wind could speed up the steam evaporation process. The concentrated brine was finally boiled to expel the last remnant of water. The finished salt was packed in barrels and transported by sea. Vallø saltworks at Tønsberg was the only saltworks in Eastern Norway. It was established by the state in 1737.
Sugar refinery, Holter series
We see the round basins where the raw sugar was heated and clarified with lime water. To the left are two rows of cone-shaped "sugar cups" of ceramic where the cooling and crystallization took place. The sugar refinery in Halden was one of the largest industrial companies of the time. The production was based on sugar cane from the West Indies.
