Augustus Hare in his book Walks in Rome (1875) describes the Quirinale and quotes this anecdote by Beste:
“It was from this same palace that Pius IX.—who has never inhabited it since—made his escape to Gaeta during the revolution of 1848, when the siege of the Quirinal by the insurgents had succeeded in extorting the appointment of a democratic ministry.
“On the afternoon of the 24th of November, the Duc d’Harcourt had arrived at the Quirinal in his coach as ambassador of France, and craved an audience of the sovereign. The guards wondered that he stayed so long; but they knew not that he sat reading the newspapers in the papal study, while the pope had retired to his bed-room to change his dress. Here his major-domo, Filippani, had laid out the black cassock and dress of an ordinary priest. The pontiff took off his purple stole and white pontifical robe, and came forth in the simple garb he had worn in his quiet youth. The Duc d’Harcourt threw himself on his knees exclaiming, ‘Go forth, holy Father; divine wisdom inspires this counsel, divine power will lead it to a happy end.’ By secret passages and narrow staircases, Pius IX. and his trusty servant passed unseen to a little door, used only occasionally for the Swiss guards, and by which they were to leave the palace. They reached it, and bethought them that the key had been forgotten! Filippani hastened back to the papal apartment to fetch it; and returning unquestioned to the wicket, found the pontiff on his knees, and quite absorbed in prayer. The wards were rusty, and the key turned with difficulty; but the door was opened at last, and the holy fugitive and his servant quickly entered a poor hackney coach that was waiting for them outside. Here, again, they ran risk of being discovered through the thoughtless adherence to old etiquette of the other servant, who stood by the coach, and who, having let down the steps, knelt, as usual, before he shut the door.
“The pope wore a dark great coat over his priest’s cassock, a low-crowned round hat, and a broad brown woollen neckcloth outside his straight Roman collar. Filippani had on his usual loose cloak; but under this he carried the three-cornered hat of the pope, a bundle of the most private and secret papers, the papal seals, the breviary, the cross-embroidered slippers, a small quantity of linen, and a little box full of gold medals stamped with the likeness of his Holiness. From the inside of the carriage, he directed the coachman to follow many winding and diverging streets, in the hope of misleading the spies, who were known to swarm at every corner. Beside the Church of SS. Pietro e Marcellino, in the deserted quarter beyond the Coliseum, they found the Bavarian minister, Count Spaur, waiting in his own private carriage, and imagining every danger which could have detained them so long. The sovereign pressed the hand of his faithful Filippani, and entered the Count’s carriage. Silently they drove on through the old gate of Rome,—Count Spaur having there shown the passport of the Bavarian minister going to Naples on affairs of state.
“Meanwhile the Duc d’Harcourt grew tired of reading the newspapers in the pope’s study; and when he thought that his Holiness must be far beyond the walls of Rome, he left the palace, and taking post-horses, hastened with all speed to overtake the fugitive on the road to Civita Vecchia, whither he believed him to be flying. As he left the study in the Quirinal, a prelate entered with a large bundle of ecclesiastical papers, on which, he said, he had to confer with the pope; then his chamberlain went in to read to him his breviary, and the office of the day. The rooms were lighted up, and the supper taken in as usual; and at length it was stated that his Holiness, feeling somewhat unwell, had retired to rest; and his attendants, and the guard of honour, were dismissed for the night. It is true that a certain prelate, who chanced to see the little door by which the fugitive had escaped into the street left open, began to cry out, ‘The pope has escaped! the pope has escaped!’ But Prince Gabrielli was beside him; and, clapping his hand upon the mouth of the alarmist, silenced him in time, by whispering, ‘Be quiet, Monsignore; be quiet, or we shall be cut to pieces!’
“Near La Riccia, the fugitives found Countess Spaur (who had arranged the whole plan of the escape) waiting with a coach and six horses—in which they pursued their journey to Gaeta, reaching the Neapolitan frontier between five and six in the morning. The pope throughout carried with him the sacrament in the pyx which Pius the Seventh carried when he was taken prisoner to France, and which, as if with prescience of what would happen, had been lately sent to him as a memorial by the Bishop of Avignon.”