Sec. 54. The plan in which the western tower is engaged within the aisles--that is, where the aisles are brought up flush with the west end of the church--is not very common. Still, instances occur in all parts of England. At Grantham, the plan is deliberate. It was imitated, as has been said, from Newark, where the side walls of the tower had been pierced with arches as an after-thought. Newark, in turn, may have taken the design from Tickhill in south Yorkshire; and the design at Tickhill may have been taken from the early and unpretentious example at Sherburn-in-Elmet. Grantham probably suggested other similar designs, such as Ewerby, near Sleaford. Several of our finest late Gothic churches, like St Nicholas at Newcastle, have plans in which the aisles are continued up to the west face of the tower. The method affords full development to the aisles, and, as at Sileby in Leicestershire, has an imposing interior effect. Outside, however, the aisles crowd the base of the tower too much, and the fine effect of a lofty, free standing tower is lost. Sometimes aisles were extended westwards, so as to engage an earlier tower, as at Sleaford, where the low tower and spire are almost overwhelmed by a pair of wide fourteenth century aisles. At Brigstock and Winterton, late Saxon towers have been left without alteration inside aisles which have been brought westward in the thirteenth and fourteenth centuries. The nave of Holy Trinity, Cambridge, was much widened in the fourteenth century, and a small tower and spire of earlier date were brought entirely within the new nave, as happened in the south aisle at St Mary's, Leicester, and were left without sufficient abutment. As a consequence, the arches of the ground story had to be strengthened about a century later with additional masonry. Cases occur, as at Coln Rogers in Gloucestershire, where a tower has been built within the west end of an earlier church. In most of such instances, the churchyard boundary probably allowed of no further building westward. The nearness of the churchyard boundary also seems to have given cause to a peculiarity which may be seen at Wollaton, near Nottingham, Dedham in Essex, and in a few other places, where the west tower is in its usual position, but is pierced from north to south by an archway. It is possible that this gave facility to processions, which could thus pass round the church without leaving consecrated ground. The tower of old All Saints, Cambridge, now destroyed, projected over the public foot-way of the street, which passed through its ground story; while St John's, Bristol, is built on the city wall, and the tower and spire, which it shared with the adjoining church of St Lawrence, are over the south gate of the city.