Many historians claim that globes can have been of little practical use in navigation - it is difficult to make accurate measurements on a curved surface and the scale is too small to plot detail. However, these criticisms pertain to the terrestrial globe, where the surface of the sphere represents the surface on which the navigator wishes to travel, and which he must therefore know in detail. This 'Starfinder' globe (Image 1), designed by one Lieutenant English and made by Cary & Co. around 1925, provides a late example of a celestial globe intended to aid with the identification of stars for use in navigation. It is not known how widely the Starfinder was used, but it most likely became redundant in the mid 20th century with the development of new navigational technologies during the Second World War.
English's Starfinder globe is well adapted for navigational use at sea. Only the most important navigational stars are depicted on the sphere, and are shown as individual points as they are seen in the night sky, rather than as imaginative constellations. The box that holds the globe is about the same size as a marine chronometer (Image 2), so it would not have been too bulky for use onboard a ship. In addition, the mahogany box protected the delicate plaster sphere from damage in rough seas and provided safe storage space for the accompanying instruction booklet and the red and blue pencils used to make the markings required for certain calculations.
