In 1888, he worked on the railroad for the first time, overseeing the construction of the Plasencia-Astorga line, and in 1896 he was hired by the Madrid-Cáceres-Portugal Company—a concessionaire that had just implemented the “multidivisional” organizational model—as a manager in the Operations Department. These fruitful experiences allowed him to demonstrate his unique abilities, which is why it was no coincidence that Norte hired him in 1904 as deputy director of M. Waldmann. It is true that Boix joined the Pereire company thanks to the “Spanishization” of its capital stock; but his immense ability is the only thing that explains why, four years later, he was appointed director of the company.

Boix had the foresight to assemble a team of his most trusted associates, consisting of young civil and industrial engineers, many of the latter having been trained at the newly established ICAI (Catholic Institute of Arts and Industries) at the university founded by the Marquis of Comillas. While the start of his tenure as a manager was aided by the favorable conditions the railway concessionaires were experiencing at the time, everything would take a turn for the worse as a result of the crisis triggered by the Great War, known as the “Railway Problem.”

Of all the issues Boix had to address, social issues were the most complex and the ones he showed the least ability to resolve. Following the teachings of Frédéric Le Play, introduced by G. Noblemaire during his tenure as general manager between 1866 and 1869, Norte was a pioneer in developing a system of “industrial welfare” consisting of schools for employees’ children, libraries, recreational centers, a company store, a loan fund, and a pension fund. It was this industrial paternalism, in fact, that led Boix to be firmly convinced that the workers were well paid, had job security, and, moreover, enjoyed many other “benefits” still unknown in most industries where similar work was performed; and, consequently, that their grievances were unjustified. But reality was no longer that of the 19th century, and, despite being warned by his associates that he must change labor relations to adapt to an increasingly powerful labor movement, he maintained an intransigent stance that led to ever-increasing and tense conflict. In the end, he had to raise wages and accept negotiation with freely formed unions as the appropriate means of resolving conflicts. Driven by his extreme consistency, Boix requested his retirement on the last day of 1918.

However, he returned a year and a half later, during which time he served as president of Canal de Isabel II, working as a director and board member alongside Alonso Martínez, the new chairman of the Board of Directors of Norte. During this second phase, the challenges were no less significant, as, in an unfavorable context for railway concessionaires, he had to defend his position during the drafting of the Railway Statute—an institutional framework approved in 1924 that made the State an equal partner with the concessionaires. In any case, his contribution was significant, as he initiated the electrification of the Spanish railway network with the Ujo-Busdongo (63 km), Barcelona-Manresa (66 km), Moncada-San Juan de las Abadesas (106 km), Alsasua-Irún (106 km), and Ripoll-Puigcerdá (106 km) sections.

Boix was also a great art collector, specializing in antique drawings, Talavera and Alcora ceramics, 19th-century paintings, and illustrated books. He combined this passion with other endeavors, such as publishing the first monograph on the painter and illustrator Francisco Lameyer (1825–1877) in 1919, organizing the first exhibition of antique drawings held in Madrid, and promoting the Exhibition of Old Madrid. All of this earned him admission, on November 8, 1925, to the Royal Academy of Fine Arts of San Fernando as a full member, with a lecture on the origins of lithography in Spain—one of the first studies on the subject. His donation of more than a thousand objects from his collections to the Madrid City Council became the foundation of the city’s Municipal Museum; in recognition of this, the city council named a street after him in the northern part of the city, near a Canal de Isabel II reservoir and Chamartín Station.

One day after his death on May 25, 1932, the Andalusian edition of ABC published a brief obituary highlighting his professional achievements and his contribution to the arts; similarly, Blanco y Negro did the same, including a photograph and stating that his death “has caused widespread sorrow; it is a considerable loss for Spain.” His work did not end with his passing, as many of his disciples took over the management of Renfe at the worst moment in the history of the Spanish railway.