4. The Astronomical photographs and photographic instruments of the 19th century Portuguese Observatories and its Relation with European Astronomers:
- Experiments and instruments used by Charles Piazzi Smyth (1819-1900) in his research on solar spectrum with an emphasis on visual representation;
- Piazzi Smith’s scientific voyages to Lisbon, Sintra and Madeira to carry out spectroscopic and meteorological research during the years 1877 to 1881;
- Study of the relation established by Piazzi Smyth with Portuguese scientific institutions, namely the “Observatório Astronómico da Ajuda”, correlated with this research we will study an important collection of photographs and related instruments kept at this Observatory.