Only recorded copy of the 1848 edition (preceded only by one recorded copy of 1846 edition) of Malby's 18 inch (45.5 cm) terrestrial globe, the largest he engraved and much rarer than his 12 inch globe. It shows small pieces of the Antarctic coast, noting sightings and explorations from 1831 to 1841. In Africa it shows Lake "Nyassi", discovered by Candido José da Costa Cardoso in 1846, but most of equatorial Africa and the Congo remain uncharted territory. "Oregon", officially made a United States territory in 1848, shows the boundary with "British America" agreed at the 1846 Oregon treaty. Alaska is still "Russian America. Texas is part of the United States, as are California and most of Arizona. The Revolution of 1848 has not yet affected the boundaries of the Austrian Empire. "Debai" (Dubai) is shown on the Gulf coast, only 15 years after the al-Maktoum dynasty took charge of it in 1833.
The globe seems to be intended especially for navigational use, with not only a grid of parallels and meridians, but also the irregular curved lines indicating the variation of magnetic from geographic north ("isogones"). Malby seems to be the first and almost the only globe maker to show them.
The horizon ring and globe have a dozen small cracks repaired and a few small gaps in the surface image, some repaired, but are otherwise in good condition. Extremely rare and lovely large globe. Cf. British Library on-line cat. BLL01013005847; Dekker, GLB0081; Dunn & Wallis, British globes up to 1850 (1999) 209 & 443; World in your hands (Rudolph Schmidt coll.) 7.12 & 7.13; Yonge, Early globes (1968), p. 46.