Secchi believed in the unity of science and constantly tried to find the connection between the solar phenomena and the meteorological and geomagnetic ones by means of intense monitoring and data recording activities. Secchi always compared and cross-checked data and gave priority to observed phenomena as he preferred the experimental approach with respect to theories and calculations, This method of conducting advanced research and his contributions to dissemination of science were often challenged, but make him a very modern scientist.
Worth mentioning – besides the already cited contributions to meteorology (the realization of the first modern governmental weather warning and forecast Service in history, the transmission of the data by telegraph, and the invention of the ‘meteorograph’) and to geodesy (measurement of the geodetic basis on the Appian Way, construction of a tower on top of Monte Mario for the geodetic triangulation of the Papal State and for the measurement of the degree of the central European meridian) – is a contribution to limnology by introduction of a disk, the Secchi disk, which is still in use for the measurement of water transparency.