Rare chart of the world published for use aboard merchant and passenger shipping, in order to mark a ships track.
With ships constantly sailing back and forth between Britain and Asia, it was essential to ensure smooth and efficient passages. To this end in the 1790s William Heather, hydrographer to the East India Company, began publishing blank charts for use by East India Company shipping, which they could use as a template to plot their tracks through the sea. The charts would continue to be published by Heather, and his successor's Norie and Wilson, through much of the nineteenth century.
The present example identifies ports and harbours at which the ships might wish to stop off, as well as various shoals, reefs, and ice that could prove to be dangerous obstacles for the unwary seaman; in addition are marked tracks of Great Circle sailing.
The chart marks two ships tracks in red. The first plots a route from Portsmouth to Launceston, Tasmania, via the newly opened Suez Canal. Stops along the way include: Gibraltar; Suez; Aden; Port Galle, Sri Lanka; Albany; Adelaide; and Melbourne. The second track plots the route from London via Plymouth to just south of the Canary Islands.
As noted below the title, the map was available in separate sheets. A navigator could buy the entire world set or just a section with specific routes/areas, depending on their needs. This set has been joined and would fold neatly, making it easy to carry on long voyages.
A note below the title states:
"GREAT CIRCLE SAILING and COMPOSITE TRACKS
On this Chart the Great Circle and Composite Tracks are laid down to those parts where such sailing is most practicable; against the Monsoons it is not available, excepting perhaps Steamers; & near to the Equator it becomes as Plane Sailing on the Mercator Chart."
A great circle track indicates the shortest distance between two points on a sphere, and therefore the most direct route. A composite, or modified great-circle, track consists of an initial great-circle track from the point of departure with its vertex on a limiting parallel of latitude.

Prick Charts
The first prick charts were published for the East India Company by William Heather (c1766-1812) in the mid 1790s, and most likely drawn by his apprentice William Norie (1772 – 1843). Norie began his career working with William Heather, who ran the Naval Academy and Naval Warehouse in Leadenhall Street from 1795, which sold navigational instruments, charts, and books on navigation. Norie took over the Naval Warehouse after Heather's retirement and founded the company J.W. Norie and Company in 1813. After Norie's death the company became Norie and Wilson, then in 1903 Imray, Laurie, Norie & Wilson.
John Statton Hobbs, was a hydrographer and chartmaker, who produced charts for Charles Wilson successor to William Norie.