This Curvilinear tower was not originally intended to carry a spire, but one was at a subsequent period added, which so severely tried the strength of the tower that at the time of the Restoration it was in so dangerous a condition that the bells could not be rung.
In the Rectilinear Period the church was further enlarged, and the following were added:—
| The present | North Aisle. |
| Outer North Aisle. | |
| North Porch. | |
| One Buttress on the South Outer Aisle. | |
| Two Buttresses on south side of Chancel. | |
| South Porch. | |
| North-east Buttress of North Transept. | |
| Stairs to Rood-loft. |
The Parish Church of Spalding presents an excellent example of how the architects of the period transformed an Early Geometrical church into a Rectilinear one.
Originally the nave and transepts were of one uniform height throughout, as were also the roofs, plates, clerestory-range, arches, capitals, and bases respectively. The pillars of the nave were heightened about 6 feet about the year 1450, when the arches were reset and the clerestory rebuilt and the present windows inserted.
The tower (Perpendicular) should be compared with that of All Saints’, Moulton, another church built by the Spalding monks. It is surmounted by lofty pinnacles and flying buttresses connecting them with a crocketed spire rising to the height of 153 feet. It is placed at the west end of the south outer aisle.
Mr. Sharpe, in his Lincoln Excursion, 1871, says: “The tower and spire rank among the finest in the country.” And writing on the church, he says: “Although its separate features have no great merit, it presents one of the most striking interiors to be seen in any parish church; due in a great measure to the variety and irregularity of its different parts, and the many singularities of designs, to which the various alterations of form have given rise, as well as to the excellent restoration it has received.
“The Chapel of St. Thomas à Becket is a curious building, the windows of which have tracery of an unusual kind, in which both right and flowing lines are introduced.
“The north porch is an important structure of somewhat late in the Rectilineal Period, with a groined fan-tracery roof and parvise over it.”