When it was decided, in the reign of Louis XIII, to double the size of the court of the Louvre, Jacques Lemercier, who was entrusted with the work, erected as a central feature of the prolonged façade, the “=Pavilion de l’Horloge=.” This was supplemented on the side facing west by another pavilion called after the famous minister of Henri IV and Louis XIII, the =Pavilion Sully=. The former occupies a width twice that of the double, projecting bays, and, while it continues the sequence of windows in the _bel étage_ and attic, introduces in the former a large round-topped window. Further, the attic is surmounted by a clerestory of three windows, framed with twin-figured caryatids by Jacques Sarrazin. They support a pediment, above which rises a domical roof, divided by four well-defined ribs and terminating in a balustraded crown--a treatment of pavilions essentially French in character. It is akin to that type of roof construction, which was called after the architect, François Mansart or Mansard, who popularised its use. The principle is the replacement of the continuous slope by a “hip” or “curb”--namely, the meeting of an upper and a lower slope at an obtuse angel; a form of construction which reduces the outward thrust on the walls by directing much of the strain to the post that supports the angle. When used upon pavilions, it gives them something of the effect of towers. =East Façade.=--Under Louis XIV the Old Louvre was completed by the addition of the east façade. The work had been entrusted to Bernini, who was a visitor at the court, but his project was rejected in favour of one designed by the King’s physician, Dr. Perrault. This involved again doubling the size of the plan by the continuation of the north and south façades. In these the style of Lescot’s was fortunately preserved, though another story was added to accommodate the extra height of the east façade. The latter represents the full acceptance of the classical style, which reflects the taste of the time; and is such a design as an intelligent student of the writings of Vignola might compile. Its main feature is a colossal order of coupled Corinthian columns, forming a colonnade, behind which the walls of the edifice are set back. The uniformity of this front of six hundred feet is interrupted by projections at the ends and in the centre, the predominance of the latter being asserted by a pediment. The character of this façade is echoed on the south one, overlooking the Seine, by an order of colossal pilasters.