Colossus Globe

Dated 1854 in private collection.


Overall, the globe was severely discoloured, due to degradation of the natural resin varnish layer. There was some cracking and losses of the plaster layer and associated loss of the paper map. There was uneven staining, which damaged the paper and some of the printed information. There were also many areas of overpaint, mostly bright green, which no longer matched the surrounding colouration of the map.


The loose plaster and paper elements were secured with conservation-grade adhesive. Once secure, the brittle, discoloured varnish was removed mechanically. After varnish removal, the surface was cleaned overall. Areas of loss in the plaster were filled with commercial putty and losses in the paper filled with hand-toned, Western papers. The surface was then sized and varnished with conservation-grade materials. Areas of loss and staining were inpainted with conservation-grade paints. Followed by a final spray-coating of varnish.

Treatment stages

Figure 1

Colossus globe, before treatment, with discoloured varnish.

Figure 2

Detail of globe, before treatment.

Figure 3

Detail of globe, before treatment.

Figure 4

Detail of globe, during treatment.

Figure 5

Colossus globe, after treatment.

Figure 6

Detail of globe, after treatment.

Figure 7

Detail of globe, after treatment.

Figure 8

Detail during treatment, paper fill.