Frames and supports in 15th and 16th-century Southern Netherlandish painting

CHAPTER X 262 The purpose of this operation was to allow the Trinity panel to be slid. To the right, just a little space was needed to allow someone’s finger to push the Trinity laterally. A single wheel under the right lateral part was therefore sufficient. To the left, more space was needed to slide further the Trinity. Perhaps the lateral left part had to be pushed backwards more or less against the box, which may have required strap hinges with a double axis system. Two little wheels under the left lateral part were therefore necessary. The upper and lower rails of the frame of the Trinity are each fitted with two wheels parallel with the painting, permitting lateral mobility, probably along two grooves, one at the top and the other at the bottom (fig. 133b). Traces of abrasion, in a horizontal direction, of the gilding of the frame of the Trinity at various heights, suggest that it was slid from time to time within a narrow space where it encountered an obstacle, very likely the reliquary while exhibited in front of the paintings. The Trinity moved sideways to permit the extraction of the reliquary, and then returned to its usual position, closing the empty box behind de reliquary. The reliquary painted by Jean Bellegambe on the Trinity panel probably resembles the original reliquary in precious metal. It was necessary to support the side elements with strong iron fittings that would hinge them to the box (fig. 129). It was important that their entire weight not lie on the wheels alone, which would have blocked the mechanism. Conclusion Overall, the altarpiece programme was modulable. We have in fact a succession of positions of the altarpiece: an initial arrangement (the altarpiece with wings closed over the Trinity) and then another one (with wings pivoted outwards). There was also a third programme: the exhibition of the ancient reliquary. We know of the reliquary that it presented, in niches, the twelve apostles, and that it was crowned in the centre with the Virgin, the Father, the Son and the Holy Spirit. It is perhaps this reliquary in precious metal that Jean Bellegambe evokes in the painting of the Trinity. The Fig. 133. The wooden wheels enabling the paintings to be moved. a. Roller under a side part. Placed perpendicular to the grain of the wood, its dimensions are limited by the thickness of the frame, while the shape of the notches witnesses to the difficulty of inserting the pin forming the rotation axis. b. Roller in the frame of the Trinity, in the direction of the grain. The pin for the rotating axis has been placed without difficulty, running through the frame. a b