Analogue calculating machines seek solutions to equations by translating them into physical phenomena. Numbers are represented by physical magnitudes such as may be done with certain rotational axes, potentials, electrical or electromagnetic states, and so on. A mathematical process is thereby transformed by these machines into an operative process of certain physical magnitudes which leads to a physical result corresponding with the sought mathematical solution. The mathematical problem therefore is solved by a physical model of itself. From the mid 19th century, various such mechanical devices were known, including integrators, multipliers, and so on ; it is against this background that Torres's work is defined. He began with a presentation in 1893 at the Academy of Exact, Physical and Natural Sciences of the Memory on algebraic machines. In his time, this was considered an extraordinary success for Spanish scientific production. In 1895 the machines were presented at a congress in Bordeaux. Later on, in 1900, la Memoria would present the calculating machines at the Paris Academy of Sciences. These machines examined mathematical and physical analogies that underlay analogue calculation or continuous quantities, and how to establish mechanically the relationships between them, expressed in mathematical formulae. The study included complex variables and used the logarithmic scale. From a practical standpoint, it showed that mechanisms such as turning disks could be used endlessly with precision, so that variables' variations were limited in both directions.