Conservation of scientific instruments in Brazil. Case study: defining the intervention criteria for the Bamberg elbow transit telescope of MAST

ABSTRACT The architectural complex of Observatório Nacional was completed in 1927, including the astronomical observation pavilions, of which one pavilion houses the Bamberg 10783 elbow telescope. All building architecture, collections and archiving funds were subject to registration by the Instituto do Patrimônio Histórico e Artístico Nacional (in 1986) and by the Instituto Estadual do Patrimônio Cultural (in 1987). The diagnosis and definition of the interventions in this Bamberg telescope of Museu de Astronomia e Ciências Afins (MAST) integrate this article. Due to cross-sectional nature of the conservator’s research going beyond materiality, we get information before any intervention in order to identify which values would be affected by possible treatments on damages and replacement parts. Utilizing a classification in 4 degrees of deterioration, taking as a tacit parameter the manuscript scratched in the varnish of the inversion elevator column, the diagnosis of the telescope revealed a significant percentage of unprotected metal surfaces, some fairly advanced localized corrosion, and a considerable percentage of uniform corrosion thin layer. The most symbolic damages on this elbow transit telescope only required minimal intervention and discussion on what would be the best course of action given the adverse conditions of its preservation in situ.