Those who wish to be acquainted with the structural secrets of the cathedral should make an effort to gain admittance to one of the spiral staircases to the upper passages that lead from triforium to triforium, from clerestory to clerestory. In these higher regions we shall still come upon deeply wrought crocketing, such as that in the upper eastern lancet windows--crocketing seen only by the stray visitor, yet worked with ungrudged labour and skill. Here we may step along the plank that takes us from beam to beam for a hundred feet over the vaulting of the Choir, through the spacious chamber that separates this vaulting from the outer roof. On every beam stands a pail of water ready in case of fire. Through a low doorway at the end we pass to the circle of the lantern. Here a shutter-like panel can be opened and we can look downwards if we will, but we shall probably elect rather to spend these rare minutes in gazing upwards, on the figure of Christ in the key boss of the vaulting, now that for once in our lives we find ourselves near enough to John of Burwell's carving to see how bold and yet how reverent it is.[229] [Footnote 229: See p. 358.] One question forces itself upon us, how was it placed here? How was Mr. Gambier Parry able to paint the glowing angels on these panels? We see in imagination the scaffolding, the ropes, the pulleys, that have been in use here, where now all is calm and rest, and we feel that William Watson might have had this very scene before him when he wrote the lines: "No record Art keeps Of her travails and woes: There is toil on the steeps, On the summit repose." The tourist has one further duty to perform; for he must not leave Ely without walking round the cathedral outside. He will then be perplexed by the anachronisms before him; he will see Perpendicular windows inserted in Norman aisles, Decorated tracery in Early English masonry; he will observe this from without more plainly than from within, and he will realise how the monks who designed and built it all had a firm belief in themselves, and in their own age, so that they did not shrink from what we should now count as acts of Vandalism. They no more hesitated to displace the work of their forefathers by their own, than we hesitate to light our houses and churches with electricity, instead of being content with the gas that was good enough for our grandparents.