Marcello's education began at the age of eight, and it was a broad education that included many subjects. He learned grammar – "the first letter", as Alessandro explained – under his father, who employed the writings of Julius Caesar, as they are "most necessary to men that have to operate the world." Ricciardo [Marcellos Vater] also taught him the more "mechanical arts," including architecture, ironmaking, baking, and the assembly of books, but for two different reasons. These subjects constituted not only a diversion from other studies, as Alessandro said, but also served "to give him perfection". [En 13] In addition, Ricciardo instructed him in the rudiments of agriculture. […] Ricciardo also devoted a significant amount of time to the instruction of Marcello in mathematics and astrologia naturale [= Astronomie].