October 17, 1878: In Venice, the Clemens family had increasingly been pressed by visitors who discovered Mark Twain was in the city. After three weeks of this, they left Venice for Florence, a ten hour train ride. They stayed at the Hotel de New York.

From page 269 The Life of Mark Twain - The Middle Years 1871-1891:

Sam and Livy yearned again for anonymity, or at least fewer claims on their time, by mid-October. For example, they were entertained along with other Americans by John Harris, the local U.S. consul, at his first-floor apartment on the Grand Canal. “We find altogether too much social life in Venice for our comfort,” Livy complained to her mother on October 13, and too many people recognized them on the street, The family fled Venice four days later by train for Florence, where they registered at the New York Hotel. Livy was mollified, alerting her mother on October 21 that “Florence is much more restful than Venice, because we have no social demands"

They remained there for eleven humdrum days, though the biographical record is largely silent on Sam's activities during this period. Only his trips to the art galleries left much of a mark. He mocked the “sappy & gushy & chuckleheaded & theatrical” paintings in the Pitti Palace collection and he was particularly outraged by Titian’s Venus of Urbino in the Uffizi, which he described in his notebook as “grossly obscene” and ‘wholly sensual.” The figure on the canvas, he asserted, “is thinking bestialities. She inflames & disgusts at the same moment. . . . Young girls can be defiled by looking at V[enus].” He elaborated his attack in A Tramp Abroad, unleashing a diatribe about the painting, labeling it “the foulest, the vilest, the obscenest picture the world possesses,” not merely because “she is naked and stretched out on a bed” but because her left hand touches her pudenda. “I saw young girls stealing furtive glances at her,” he added. “I saw young men gaze long and absorbedly at her; I saw aged, infirm men hang upon her charms with a pathetic interest. .. . Without any question it was painted for a bagnio” or brothel.