§ 30. The magnificent architectural development of the tower and spire, in which, as in perhaps no other part of the church, the individual characteristics of local schools of masoncraft can be traced, becomes noticeable in the thirteenth century, at a time when the use of the ground floor of the tower as the principal porch of the church had been discontinued. In the fen country round Wisbech and Spalding, a series of thirteenth century towers, covering the period from 1200 to 1280, bears witness to the work of a school of tower builders, hardly less distinguished than the great Somerset masons of later days, which probably derived its inspiration from the arcaded western tower of Ely cathedral. Elm, Leverington, Walsoken, West Walton, Tilney All Saints, Long Sutton, Gedney, and Whaplode, are the principal evidence of their work. Not all these towers are western, and four of the number, including Gedney, the belfry stage of which belongs to a later date, are without the spires which their builders doubtless intended; but all are instances of the treatment of the bell-tower as an independent architectural composition, quite irrespective of its part in the plan of the church. In the twelfth century, however, when the side doorway was superseding the tower porch, the western tower was by no means so handsome or invariable a feature as it became in later days. Many smaller churches were content with a bell-cot over the western gable. There are several excellent examples of stone bell-cots in Rutland. In Essex and other districts where good building timber was easily procured, it is not uncommon to find square towers of timber, with conical caps or even spires, above the western gable, often supported on an elaborate framework within the west end of the church. A few timber towers, like Margaretting in Essex, are built up against the old west end of the church.