Salisbury Cathedral and Chichester Cathedral, 1402 to 1861) and fallen down; instead, Salisbury became the tallest church spire in the country on the collapse at Lincoln in 1549. The large supporting pillars at the corners of the spire are seen to bend inwards under the stress. The addition of reinforcing tie-beams above the crossing, designed by Christopher Wren in 1668, halted further deformation. The beams were hidden by a false ceiling, installed below the lantern stage of the tower. Significant changes to the cathedral were made by the architect James Wyatt in 1790, including replacement of the original rood screen and demolition
Cathedral of Learning deliver the stone on schedule, so construction was delayed, and work began on the higher stories. When construction started on the Cathedral of Learning in 1926, it was the tallest building in Pittsburgh, although the Gulf Tower (1932) was completed and surpassed it by the time the Cathedral of Learning was officially dedicated in June 1937. Today, it remains the tallest educational building in the Western hemisphere, the second tallest university building in the world behind the 36 story, 240 m (including a 57 m spire) Moscow State University main building completed in 1953, and the fourth tallest educational building