Naval navigation and the discovery of Longitude

The following items were featured in a temporary display in the Founders' Room during the installation of Ships, Clocks and Stars: The Quest for Longitude, one of the Exhibitions at the Folger in 2015.

This display was curated by Caroline Duroselle-Melish, the Andrew W. Mellon Curator of Early Modern Books and Prints at the Folger Shakespeare Library.

Item Label

Samuel Fyler, 1638-1703.

Longitudinis Inventæ Explicatio Non Longa, Or, Fixing The Volatilis’d, And Taking Time On Tiptoe, Briefly Explain’d ...

London : printed for the author, in the year, 1699.


Although the title of this pamphlet led one to believe that it only dealt with finding longitude at sea, the author’s main concern was the moral life of seamen both on board and on land. Samuel Fyler, a rector in the parish of Stockton near Salisbury, wrote his pamphlet in the form of a dialogue between the author and “an intelligent seaman.” While the first part of the dialogue pertained to the utility for mariners of following the longitude at sea, the second part explained why “the longitude of eternity in [their] thoughts” was really what mattered. The author apparently found an audience for his text, which was printed at his own expense, for he had it reprinted a year later in 1700. The copy on display, stitched and unbound, is in the state in which it left the printshop.

Jan Collaert, 1566-1628, printmaker.

[The Invention of the Compass], Lapis polaris, magnes

[ca. 1591].

ART Vol. f81 no.2

The two prints on display belong to the first series of engravings ever produced depicting modern technological inventions. These prints were made after drawings by the Flemish artist Johann Stradanus, who worked for the Medici court in Florence, including for Grand Duke Francesco I de Medici who had an interest in science. The present image probably depicts Flavio (or Flavius) Gioia, who was wrongly viewed at the time as the inventor of the compass, which was useful for navigation. Flavio is depicted in his studio with his research tools, namely, his books and scientific instruments. The boats of the ancients are visible by the window in the background. Their simple design contrasts with the model of a sophisticated modern ship hanging in Flavio’s studio.

Jan Collaert, 1566-1628, printmaker.

[The Discovery of the Establishment of the Longitudes]. Orbis longitudines repertae e` magnetis à polo declinatione.

[ca. 1591].

ART Vol. f81 no.16

Stradanus’s rendering of a scientific discovery is here more artistic than accurate. The artist has depicted Petrus Plancius using an azimuth compass to determine the position of the sun instead of the magnetic compass Plancius had invented to establish the longitudes. The boat on which the inventor is sailing is massive and sophisticated enough to overcome powerful storms at sea. The heads of canons, another early modern innovation, point from several openings on the ship.