  The solar program of the Astronomical Observatory of Madrid started in 1876.
For ten solar cycles, observations were made in this institution to determine
sunspot numbers and areas. The program was completed in 1986. The resulting
data have been published in various Spanish scientific publications. The
metadata allowed four periods of this program (with different observers and
instruments) to be identified. In the present work, the published data were
retrieved and digitized. Their subsequent analysis showed that most of these
data can be considered reliable given their very high correlation with
international reference indices (International Sunspot Number, Group Sunspot
Number, and Sunspot Area). An abrupt change emerged in the spots/groups ratio
in 1946 which lasted until 1972.
