The mounting plate on the bar connects to the bottom rail of the sash window. It's also used by counterweights for lifting up an elevator, crane, or sash window. There are two original pedimented roof dormers, each with a 6-pane sash window. This is the earlier form of sliding sash window, and is also cheaper. The stair is lit by a tall sash window. The early main entrance is infilled with timber boards and a sash window. Each lower bay has a sash window. This has a four-panel timber door with fanlight and a sash window to the platform. In the middle bay is a round-arched doorway, now blocked but containing a sash window. Others see the sash window as a Dutch invention. Selling through a sliding sash window would remain the trademark of the brand for decades. The invention of the sash window is sometimes credited, without conclusive evidence, to Robert Hooke. There is a third sash window located in the center. The chamfered corners each contain a single sash window per floor. There is a double-hung sash window in the rear wall.