Positive Organ
It is a small organ with light and small tubes and can be moved.
German positive organ (17th century)
Musical Instruments Museum (MIM) - Brussels - Belgium
How does it work?
It works just as the big pipe organ. Their sounds are emitted through the passage or air under pressure in their pipes, which has its mechanism triggered by keyboards.
A bit of history...
One of the earliest accounts that reference to the organs in Rio de Janeiro can be found in the Monastery of St. Benedict, dating from 1562. It is the acquisition of a positive organ for 45 $ 320 reis.
In the 18th century, in 1786, during the wedding celebrations of infants D. João and Carlota Joaquina, held around the Public Garden in the city, a positive organ with its organist and bellows' man composed the last float of the parade.
In Minas Gerais there is a surviving example of colonial period. This is a positive shaped organ cabinet, with 223 tubes and by the use of local materials ir appears to have been built at São João del Rei region, where it has been installed and is still to this day.
Positive organ probably from a Brazilian constructor (second half of the 18th century)
Regional Museum of São João del Rei - MG