Horizontal limnigraph. Around 1920.

Limnigraph, belonged to De Marchi, similar to the previous one but with modifications to the transmission of the float displacement. A clockwork mechanism is used for the marking time but the paper advancing is determined by two symmetric weights rotating the roller of recording paper. It was used occasionally in the 30s but the systematic measure of Lake Maggiore level began in 1952, initially with daily readings of a staff gage and, from 1957, with a hydrometrograph.