It will be necessary here to give some figures and proportions of this ancient keep. Its height is 90 feet from ground to battlements. The Keep has four turrets, three being circular, and one square. The windows were much modernised by Sir Christopher Wren, but those in the upper storey are the least altered; only one pair of these, however, have been left in their original state. It was from this window that Bishop Flambard is said to have made his escape. A stone staircase, 11 feet wide, and built in the circular turret on the north-east of the Keep, communicates with all the floors and leads to the roof. The basement of the Keep is a little below the level of the soil on the north side, and is flush with it on the south side. The walls are from 12 to 15 feet thick, the internal area being 91 feet by 73 feet. The large chambers have timbered ceilings, and the smaller are stone-vaulted. Formerly, the basement and the prison within it could only be reached from above, by the staircase running through the circular turret. The great western chamber is 91 feet long by 35 feet in width. In the vault or sub-crypt under the Chapel of St John there is a prison called “Little Ease,” and here Guy Fawkes is supposed to have passed his last fifty days on earth. It opens into a great dungeon which is 47 feet long by 15 feet broad. Formerly, this place was in total darkness, and could have had but little air; at its eastern end it terminates in a semicircle. It was here that in the reign of King John some hundreds of Jews were imprisoned with their families. In later times it was fitted up into a powder magazine, and it is not many years since it was cleared of “villainous” saltpetre. Its walls have been coated with brick, and the ceiling refaced and vaulted, whilst passages have been pierced through its eastern and western extremities. A well 6 feet wide, its sides lined with ashlar stone, which may be of Roman origin, has been found in the floor of this vault, near its south-western angle. [Illustration: _Stone Staircase in the White Tower._]