Rare Survival -- Navigational Aid at Sea with Pricking Marks
Rare, separately-published Norie world map on a Mercator Projection, the preferred projection for tracking voyages at sea.
Originally printed in the 1810s, the present map was updated in 1820, and later revised and corrected to 1830. Unlike most pricking maps from before 1830, this is a complete map of the world, rather than a fragment of the whole focused on a single voyage. The map shows the tracks of voyages between the coast of France and Marie Galante in the Caribbean, and Rio De Janeiro.
The maps could be used in fragments (based upon the sailing route), as well as complete. The survival rare is very low, especially complete maps.
Dead reckoning and pricking maps
When not navigating with celestial navigation, or in conjunction with it, mariners could estimate their position on a journey via dead reckoning. With dead reckoning, the navigator finds their position by measuring the course and distance they have sailed from a previous point. This is marked on a chart over several days, creating a running record of location at sea. Thus, effective dead reckoning depends on accurate, well-made instruments, as well as on correct calculation and recording by the mariner.
The speed of the ship can be measured using a lead and line and/or the ship’s instrumentation, depending on the ship’s type and technology. A magnetic compass will tell the heading, or direction, of the ship; the compass was invented in China and has been in use in Europe since at least 1183.
Once the speed and heading are known, and the time of travel is also known, the mariner can calculate the distance traveled in which direction. Starting from a known point, the navigator measures out his course and distance from that point on a chart, pricking/dotting the chart with the tip of a pair of dividers to mark the new position. Each day's ending position would be the starting point for the next day's course-and-distance measurement.
Dead reckoning would be only one of a variety of techniques available to the navigator in the mid-nineteenth century, when this chart was made. They would have also been able to take celestial navigation observations using intricately-made instruments, as well as consult tide, wind, and lunar distance tables. Dead reckoning would be used in addition to and in conjunction with these methods, making the routes marked here the best guess of the mariner.
Pre-1840 pricking charts are very rare, especially those with the entire world present.
John William Norie (1772 – 1843) was a publisher of nautical books held in high regard by his contemporaries. He also specialized in nautical charts and was a mathematician. Norie was born in Wapping, London, the eldest of eight children.
Norie had an apptitude for navigation and chart making. His first work was published in 1796, The Description and Use of Hadley's Quadrant, by William Heather, a chart and instrument seller. Heather then took Norie on as a chart maker and allowed him to run a nautical academy out of Heather's premises on Leadenhall Street. He continued to work for Heather, working out of his shop.
Norie published many works, but the most famous were A Complete Set of Nautical Tables (1803) and the Epitome of Practical Navigation (1805). Both were reissued throughout the nineteenth century, usually together. The Tables are still issued today. The Epitome became the standard work on navigation; it was so famous that authors C. S. Forester and Jack London both mention the book in their fiction. In addition to the Epitome, Norie wrote the The shipwright's vade-mecum (1822), Plates Descriptive of the Maritime Flags of All Nations (1838), and The naval gazetteer, biographer, and chronologist; new and improved (1842). He also provided pilots with charts that covered practically the entire world's seas--the famous blue-back charts.
Norie partnered with a financial backer, George Wilson, to buy Heather's business upon Heather's death in 1813. In addition to the nautical academy and the copyright to his books, Norie prospered from the growing business, which he managed. The shop, operating under the sign of the Wooden Midshipman, was called the Navigation Warehouse. It featured in Charles Dickens' Dombey and Son.
Norie retired in 1840. He sold his shares in the business and moved to Edinburgh. He died there, at the age of 71, on Christmas Eve 1843. His company was renamed Norie & Wilson after his retirement. In 1903, the firm merged with rivals and became Imray, Laurie, Norie & Wilson. It is still in business today.