The text is edited, with 'Annotated Indices and an Introduction'. In addition to the treatise, the volume contains 'Sailing Directions for the Circumnavigation of England, and for a Voyage to the Straits of Gibraltar, from a 15th Century MS' which originally appeared as Volume 79(b) in the series. The two sets of directions were originally bound together but separately paginated. The first contains the text of the 1638 English translation, A learned treatise of globes by John Chilmead (but 'usually attributed to Edmund Chilmead with apparent corrections'); the title-page of the Latin original is dated 1594. The 'Sailing Directions' are edited, with an account of the MS., by James Gairdner; with a Glossary by Edward Delmar Morgan. This is a new print-on-demand hardback edition of the volume first published in 1889.