Alexander von Humboldt took part in the Enlightenment program of travel: he conceived it not only as a subjective cognitive experience but also as a method of construction of scientific knowledge, which, he believed, had to be spread and disseminated. Between 1805 and 1834, he published his massive work, the thirty tomes of the Voyage, concerning the trip he made between 1799 and 1804 in the ‘equinoctial’ American regions. The study focuses in particular on the journey narration (Relation Historique) and on the texts (the Atlas geographic-physical and the Atlas pittoresque) dedicated to the display of spaces and phenomena observed and ‘measured’ by Humboldt in a region still largely unknown in Europe. Taking into account the more significant critical literature, I mean to return on connections between the different languages of the scientist-traveler – the ones usually used in writings (words) and those typical of the analog and abstract visualization (landscape painting, ‘techniques’ tables, maps) – placing them in the specific Humboldtian theoretical positioning: the comparative method, the mountain as privileged analytical category and the landscape have to be considered not as aesthetic category to translate into exquisitely picturesque images but as manifestation of the concrete reality of the world.