Galilean moons century when other inner moons were discovered, and Marius' names became widely used. Galileo was able to develop a method of determining longitude based on the timing of the orbits of the Galilean moons. The times of the eclipses of the moons could be precisely calculated in advance, and compared with local observations on land or on ship to determine the local time and hence longitude. The main problem with the technique was that it was difficult to observe the Galilean moons through a telescope on a moving ship; a problem that Galileo tried to solve with the invention of
Hermanos Conde themselves ""Sobrinos de Domingo Esteso Conde Hermanos"" (Esteso's Nephews, Conde Brothers) or ""Hermanos Conde Sobrinos de Domingo Esteso"" (Conde Brothers, Esteso's Nephews). Mariano Sr. later established his own shop close to the Royal Theatre, calling it "Conde Hermanos Sucesores Sobrinos de Esteso". His two sons, Felipe, born in 1957 and Mariano Jr., born 1959, began their apprenticeship with their father and uncle Faustino when they were about 15 years old. Faustino died in 1988 and Mariano Sr. in 1989. Felipe and Mariano Conde (sons of Mariano Conde Sr.) manufactured flamenco guitars in their workshop at Felipe V St. nº 2