At Potsdam and near by Schinkel’s pupil Persius, before his untimely death only four years after Schinkel’s, produced many other compositions of this order, often by remodelling eighteenth-century buildings.[52] Two of the finest are the Pheasantry, which is specifically a towered Italian Villa, and the group that includes the Friedenskirche, carried out by others from Persius’s designs in 1845-8 (Plate 15). In this latter group the principal feature is a close copy of an Early Christian basilica, even to the inclusion of a real medieval apse mosaic brought from Murano; yet compositionally the group is a masterpiece of the classically ordered Picturesque, rivalling Schinkel’s Gardener’s House in subtlety and elegance. Even more personal to Persius is the delicacy of detailing and the unusual external arcade of his earlier Heilandskirche of 1841-3, with its graceful detached campanile, by the lakeside at nearby Sakrow. Also notable are his steam-engine houses, particularly that for Schloss Babelsberg. The inclusion of medieval and even Islamic detail indicates the increasing eclecticism of taste around 1840; yet the disparate elements are so scaled and ordered as to compose into an asymmetrical pattern of Italian Villa character in which the minaret-like chimney provides the dominant vertical accent. Less Picturesque is the Orangerieschloss, based on a sketch by Frederick William IV and executed after Persius’s death by A. Hesse. Schinkel’s big Potsdam church, the Nikolaikirche, designed in 1829 and built up to the base of the dome in the years 1830-7, stood right in the town, not in the park like his work for the princes, and is a wholly formal monument. It was planned as a hemisphere above a cube in the most geometrical mode of Romantic Classicism. As in the case of Soufflot’s dome of the Panthéon, this was undoubtedly influenced by Wren’s St Paul’s in London which Schinkel had seen on an English voyage in 1826. Unfortunately Persius had later to add corner towers, almost like the minaret chimney of his Babelsberg engine house, in order to load the pendentives when he completed the church in 1842-50. These irrelevant features quite denature Schinkel’s formal intention. The interior, however, is superior to those in most of the centrally planned churches of this period in various countries that were based on the Roman Pantheon.