？Os olhos da Geologia？, o discurso dos engenheiros e o saber dos geólogos: o início da utiliza？？o de métodos geofísicos na prospec？？o de recursos minerais em Portugal

in 1918, the portuguese geological survey (pgs) became part of the general directorate of mines and geological survey (gdmgs), and the rough times the institution was facing by the end of the 19th century turned even worst. the pgs struggled with the lack of money and specialised personnel, and was enable to develop a solid and significant geological research, especially concerning geological mapping. this circumstance was partly responsible for the difficult situation of the portuguese mining sector, and in order to modify this state of affairs the portuguese dictatorship, the estado novo, created in 1939 the service for mining development (smd). just like the pgs, the smd was also legally attached to the gdmgs. during the 1940？s, the mining engineers of the smd defended the use of geophysical methods in the prospecting of mineral resources. geophysical methods embodied some scientific values that were highly regarded by the portuguese engineers, such as rationality and objectivity. however, they were well aware that the use of ？the eyes of geology？, as geophysical methods were sometimes named, involved complex questions, such as the reading and interpretation of the results obtained. the engineers？ perspective corresponded to an attitude characteristic of a scientific ethos that became common during the 20th century. when the use of geophysical methods effectively began, the smd bought seismic equipment to a sweden enterprise and began working in a region of mainland portugal known as the diapiric valley. georges zbyszewski (1909-1999), the only geologist who worked for the pgs at the time, was appointed to follow up the geophysical campaign. the present paper argues that the work carried out by zbyszewski was highly regarded by the mining engineers leading the gdmgs. this was possible because he was using instruments subscribed by the portuguese engineers in this way reassuring them about the scientific character of his geological research. this circumstance alli