Description
The navicula is a rare and intriguing form of portable sundial, designed to resemble the shape of a ship. The earliest known examples date from the late Middle Ages, of which only five examples survive. This instrument is a later nineteenth-century copy.

The dial tells time at any latitude between the tropic of Cancer and the Arctic circle in equal hours, and all of the known examples have an unequal hour diagram on the back. There is also a shadow square, which enables the user to calculate the linear height of an object. Some scholars believe that the Zaouraq, a type of astrolabe described in early modern Arabic manuscripts, was the navicula’s precursor; however, it remains unclear who invented the first instrument and recent scholarship persuasively suggests an English origin for the navicula, perhaps in East Anglia.
19/06/2017
Created by: Josh Nall on 19/06/2017

Description
There are only six known examples of naviculae. The instrument is a small portable sundial designed in a ship-like shape. The known examples range in size between 10–15cm. The sundial tells time at any latitude in equal hours, and all of the known examples have an unequal hour diagram on the back. There is also a shadow square, which provides rough answers to calculations too difficult for the non-mathematician. Some scholars believe that the Zaouraq, a type of astrolabe described in early modern Arabic manuscripts, was the navicula’s precusor; however, it remains unclear who invented the first navicula. In 1560, the French mathematician Oronce Fine published a book about sundials, which described how to make a Regiomontanus dial and a ship-shaped dial. It included diagrams of the finished instruments. The Whipple Museum's ship-shaped dial is an exact copy of the diagram given in Fine's book. It is possible that an educated English gentleman read Fine's book and commissioned an instrument just like the one in the diagrams.
08/07/2014
Created by: Allison Ksiazkiewicz on 08/07/2014