On July 28th, 1791 Betancourt begins his trip back to Spain. He takes the opportunity to stopover at Lyon and see its manufactures, to see the possibility of installing a dredge of his invention in Barcelona and to carry out a reconnaissance of the industries and roads of Valencia. Soon after returning to Madrid, he ascends to captain of insular militias of the regiment of La Orotava in November.

Produce of the activity of Betancourt’s team was the formidable collection of two hundred and seventy models of machines, three hundred and fifty nine plans and ninety nine memoirs brought from Paris to Madrid in forty-two big boxes, in 1791, containing the most avant-garde engineering information of the time in Europe.[See part of a letter half-written with his brother from Madrid to his father October 26^th, 1891: Letter 14].

At the end of January 1792 he is named captain of the Garachico Regiment and he begins to attend regularly the sessions of the Academia de San Fernando. Later, he is named knight of the Order of Santiago. [See Betancourt’s genealogical tree; it was presented to ascend in the nobility].

The Real Gabinete de Máquinas del Buen Retiro de Madrid (Royal Cabinet of Machines at Buen Retiro, Madrid) was opened to the public on April 1st and Betancourt presents his Catálogo de la Colección de Modelos, Planos y Manuscritos que de orden del Primer Secretario de Estado ha recogido en Francia Don Agustín de Betancourt y Molina.

The following summer he is chosen to form a commission of the Academia to improve its teaching, with other personalities such as the painter Goya, who will paint his portrait at this time. A dredge of his invention, that he will use later at the Russian port of Kronstadt, is presented by Betancourt to clean the ports of Cádiz and Cartagena, but it was rejected because it was too powerful.

On October 14^th he is named Director of the Gabinete de Máquinas, although during his absence it will be López de Peñalver and others who are in charge of the management of the institution.

In March 1793 he presents to the Academia de San Fernando some models made of wood and string to explain theorems and mathematical laws of perspective, also he carries out demonstrations with an apparatus of his invention to draw landscapes and objects with an eye piece synchronized with a pencil.

Godoy visits the Gabinete de Máquinas in July. Betancourt who is not feeling comfortable in Spain decides to go to England, as France is still in a Revolutionary turmoil. He sends his wife and daughters to London in August and he himself goes in October. He receives a pension in addition to his position to collect machines in England for the Gabinete and to develop his inventions. [See Letter to his parents –with the order of the Duque de Alcudia (Godoy)- February 27^th, 1793: Letter 15].