Seeing that the “aesthetic theory” is unsupported by documentary proof, evidence must be sought in the possible existence of similar contrivances associated with other architectural features. Can such evidence be produced? The reply is in the affirmative. As one enters certain Egyptian temples, he perceives a gradual transition from light to darkness. This effect is brought about by the forced ascent of a few steps, combined with a lowering of the roof; thus the sense of gloom and mystery increases as the worshipper moves forward[590]. Again, we find that, in the columns of the Parthenon and other Greek buildings, there is an entasis, or slight convexity of outline, perchance not more than the length of a finger nail, yet sufficient to prevent the appearance of hollowness. The Parthenon is said to possess scarcely a vertical or a horizontal line throughout the whole design. The columns lean a little inwards, the corners incline diagonally, the entablature is curved and recedes in the centre[591]. Such subtle niceties, trivial when taken singly, prove that, in Classical times at least, the aesthetic phase of architecture was not ignored. The next question is, Can parallel instances of design be observed in our own country? The Norman church of Barfreston, Kent, may be cited. In this building, the axes of the nave and chancel correspond, but the walls of the chancel are so built that this portion appears to incline about 5° North. One can hardly find a rectangle in the plan of the church--“everything is oblique[592],” and apparently oblique by intention. Again, the South arcade of the nave of Scarborough parish church has a distinct curve, as if deliberately thus planned. In the case of Whitby Abbey, before cited, Canon Atkinson discovered another intentional irregularity. The West wall of the North transept projects into the interior at least a foot more than does the East wall. The view, being thus interrupted by the broken line, has a pleasing effect upon the mind of the spectator. Consider, too, the churches, to be met with in many a village, in which the pillars and mouldings of the Northern arcade are simpler than those of the Southern, the Northern windows less rich in tracery, the specimens of painted glass more sombre in motive and execution. It will be understood that a reservation must be made for those churches in which the South arcade is of slightly later date than the North. The symbolism of the Northern aspect of Nature must have been clearly appreciated for these conditions to have arisen (see p. 334 _infra_). Or, take the feature just alluded to as entasis, by which the optical illusion of hollowness in upright lines is corrected. Many of our spires exhibit this convexity. Mr Francis Bond, a high authority on such matters, states that the entasis probably does not exceed 1 inch for 60 feet in our best examples of Gothic spires. The important point to notice is, that the curvature exists as the result of design.