Switzerland's National Hydrological Survey arranged in 1908 a thorough investigation of the water level fluctuations of the Lake Märjelen. Here, a comprehensive study of this extraordinarily beautiful glacier border lake was elaborated, and published as a book in 1915. In order to detect the changes of the water level precisely, a gauge system was installed in 1908 and 1909. The cast-iron, scaled gauge panels were anchored individually or stepwise in groups in the, smooth grinded rock ledges at the former lake shore. Today, these bars are high up on the valley slope, above the «Moränensee» on the way from the glacier to the mountain hostelry «Gletscherstube».