These upper regions, hidden in an almost perpetual gloom, were decorated in monochrome by Sir James Thornhill; but his work has failed to resist the chemical action of the surcharged atmosphere. Yet a word or two about it may interest. Concentric circles surround the opening; and the remaining surface is ingeniously divided into eight compartments by designs of piers and round arches; the piers coinciding with the eight recesses below. In these compartments are scenes from the life of the patronal saint: (1) The Conversion, (2) Elymas, (3) Cripple at Lystra, (4) Jailer at Philippi, (5) Mars Hill, (6) Burning Books at Ephesus, (7) Before Agrippa, (8) Shipwreck. We have all of us heard from the days of our boyhood or girlhood the story of the painter, on a platform at a great height, who stepped back to get a better view of his work. As he did so, an assistant, standing by, brush in hand, observed with alarm that the slightest further backward step would entail his falling headlong and being dashed to pieces. He deliberately daubed the painting; and the artist, stepping instinctively forward to prevent this, saved his life. The painter is said to be Thornhill: the scene, the giddy height under the dome.
The interior height of two diameters will always be a disputed question. Stephen Wren[101] seemed to think that his grandfather hit the happy medium of a diameter and a half; but this only reaches to the windows and Early Fathers. He probably gives us the Surveyor's _intention_. Afterwards, when Wren was compelled to raise the height of the exterior, he increased the interior. St. Sophia and the Invalides are both less than two diameters, and give the idea of greater area. While it is difficult to see what æsthetic advantage is gained by a roof and upper regions immersed in perpetual gloom, the acoustic properties and the light might both have been improved by a more modest elevation. Yet the advocates of a smaller ratio injure their case by writing about "a great disproportioned hole in the 'roof.'"
=The Pulpit= was one of the additions suggested in Dean Milman's time, when the dome area was used for service. It is a memorial to Captain Robert Fitzgerald, designed by Mr. Penrose; and the marbles come from various places. It stands on columns, of which the gray are from Plymouth, the "dark purplish" from Anglesea, and the red from Cork. In the panels and elsewhere the green is from Tenos, and the yellow chiefly from Siena, with a little of the ancient Giallo Antico from Rome.[102] Alike in the design, and in the combination of these different marbles, the pulpit is a fitting and judicious adornment. =The Lectern= takes the familiar form of an eagle, and is of bronze. This fine piece of work was finished in 1720 by Jacob Sutton, at a cost of £241 15s.