identifying attributes carried by many personifications until the 19th century. From the 20th century into the 21st, the past use of personification has received greatly increased critical attention, just as the artistic practice of it has greatly declined. Among a number of key works, The Allegory of Love: A Study in Medieval Tradition (1936), by C. S. Lewis was an exploration of courtly love in medieval and Renaissance literature. Innovation The classical repertoire of virtues, seasons, cities and so forth supplied the majority of subjects until the 19th century, but some new personifications became required. The 16th century saw the new personification of the Americas, and made the four continents an appealing new set, four figures being better suited to many contexts than three. The 18th-century discovery of Australia was not so quickly followed by an addition to the set, if only for reasons of geometry; Australia is not included in the continents at the corners of the Albert Memorial (1860s). This does have a set of three-figure groups representing agriculture, commerce, engineering and manufacturing, typical of the requirements for large public schemes of the period. A rather late example is the Alexander Hamilton U.S. Custom House in New York City (1901–07), which has large groups for the four continents by the entrance, and 12 figures personifying seafaring nations from history high on the facade. The invention of movable type printing saw Dame Imprimerie ("Lady Printing Press") introduced to the pageants of Lyons, a major printing centre, along with "Typosine", a new muse of printing. A large gilt-bronze statue by Evelyn Beatrice Longman, something of a specialist in "allegorical" statues, was commissioned by AT&T for the top of their New York headquarters. Since 1916 it has been titled at different times as the Genius of Telegraphy, Genius of Electricity, and since the 1930s Spirit of Communication. Shakespeare's spirit Ariel was adopted by the sculptor Eric Gill as a personification of broadcasting, and features in his sculptures on Broadcasting House in London (opened 1932). National personifications A number of national personifications stick to the old formulas, with a female in classical dress, carrying attributes suggesting power, wealth, or other virtues. Libertas, the Roman goddess of liberty, had been important under the Roman Republic, and was somewhat uncomfortably co-opted by the empire; it was not seen as an innate right, but as granted to some under Roman law. She had appeared on