sentences:  His work at the Maritime Observatory in Trieste led him to study oceanographical questions, for example on tides and the determination of water levels in Trieste harbour, both very important practical problems.With his entry to the "Gradmessungsbüro" in 1921 he turned to geomensuration and geophysics, in particular his work on the meridian arc Großenhain-Kremsmünster-Pola, which detailed the use of comparisons of vertical deflections.Later he studied the important problem of the geoid (the Earth's shape), for example through the reduction of observations of weight and the subject known as isostasy (the study of gravitational equilibrium within the Earth).