The ‘Isolario’, or ‘book of islands’, was a cartographic form introduced and developed in Italy during the 15th and 16th centuries. Like the portolano, or pilot-book, to which it was related, it had its origin in the Mediterranean, as an illustrated guide for travellers in the Aegean Archipelago and the Levant. Bordone’s ‘Isolario’ was the second to be printed and the first to give prominence to the transatlantic discoveries. Skelton quotes Almagia as saying that it is, in fact, ‘the earliest complete work of its kind to have been produced by the printing-press in Italy or anywhere else.’ The ‘Isolario’ is divided into three books, devoted respectively to the ‘islands and peninsulas’ of the western ocean, to the Mediterranean, and to the islands of the Indian Ocean and the Far East. While this order corresponds very roughly to that of Ptolemy, it gives conspicuous priority to the discoveries across the Atlantic.

The most desirable map in the atlas is this classic oval world map, for many years thought to be the first printed in this projection. It is in fact derived from the exceedingly scarce Francesco Rosselli map of c.1508. However unlike the Rosselli, Bordone omits the unknown land at the South Pole and separates the continents of Asia and America. The six traditional wind directions are marked and named outside the map. This example is from the second of four editions which was published in 1534. It is the earliest obtainable world map in an oval projection. Bordone (1460-1531) was a Paduan illuminator and wood-engraver who was apparently established at Venice by 1494. Skelton, TOT facsimile edition; Harrisse ‘Bibliotheca Americana Vetustissima’, no. 187; Nordenskiöld, A.E. (Facsimile) pp. 103-4; Shirley World 59; Skelton Introduction to facsimile edition; World Encompassed no. 83.