• Title : A New Chart of the Baltic or East Sea Drawn Principally from the Maritime Surveys Collected in the Russian Neptune compared with the Observations of the most experienceed Pilots, and Chiefly with the Charts and Draughts of Professor Christian Charles Lous, Nils Mareluis and James Schmid Published by Authority at Copenhagen, Stockholm and St Petersburg...London Published by Laurie & Whittle No 53 Fleet Street as the Act, 12th May, 1794
• Size: 48in x 39in (1.225m x 1.015mm)
• Condition: (A) Very Good Condition
• Date : 1794
• Ref #:  93046

Description:
This is a very large, extremely rare, copper-plate engraved and highly detailed working Blueback Nautical Chart or Maritime map of the Baltic or East Sea was engraved in 1794 and published by the Laurie & Whittle firm, London 1794. The details for this map have been collected from expeditions by the ship the Russian Neptune and Professor Christian Charles Lous, Nils Mareluis and James Schmid.
This rare Blueback map, a method of mounting working sea charts that was begun by Robert Sayer in the late 18th century. These working maps were extremely expensive to buy and labour intensive to put together so only a limited number were published and sold and even fewer have survived. I have found no other examples of this map either commercially or in other map collections.
The map depicts the Baltic Sea from Scandia Sweden & Pomeranian, Germany in the west to the Baltic States of Estonia and Latvia (Eastland, Livonia, Courland) & southern Finland in the east. The map is highly detailed with numerous cities are labelled, including Copenhagen, Stockholm (Christiana), Gdansk (Dazing), Tallinn (Revel), and Riga. Myriad depth soundings are indicated in the Baltic Sea and along the coastlines. Numerous inset maps are included, the first of Copenhagen and the Straits, the second of Stockholm and directions through the various channels and islands, the third inset is Rogerwick Bay, the fourth is the Island of Gottland and the fifth of Riga and Bay. Copious notes about sailing directions, channels, entrance to the Duna River.

General Definitions:
Paper thickness and quality: - Heavy and stable
Paper color : - off white
Age of map color: - 
Colors used: - 
General color appearance: - 
Paper size: - 48in x 39in (1.225m x 1.015mm)
Plate size: - 48in x 39in (1.225m x 1.015mm)
Margins: - Min 1/2in (12mm)

Imperfections:
Margins: - Soiling, chipping to edges not affecting the image
Plate area: - Soiling, light brown spots top of map, light creasing
Verso: - Original Blueback

Background: 
Blueback Charts
Blueback nautical charts began appearing in London in the late 18th century. Bluebacks, as they came to be called, were privately published large format nautical charts known for their distinctive blue paper backing. The backing, a commonly available blue manila paper traditionally used by publishers to warp unbound pamphlets, was adopted as a practical way to reinforce the low-quality paper used by private chart publishers in an effort to cut costs. The earliest known Blueback charts include a 1760 chart issued by Mount and Page, and a 1787 chart issued by Robert Sayer. The tradition took off in the early 19th century, when British publishers like John Hamilton Moore, Robert Blachford, James Imray, William Heather, John William Norie, Charles Wilson, David Steel, R. H. Laurie, and John Hobbs, among others, rose to dominate the chart trade. Bluebacks became so popular that the convention was embraced by chartmakerJacques Nicholas Bellins outside of England, including Americans Edmund March Blunt and George Eldridge, as well as Scandinavian, French, German, Russian, and Spanish chartmakers. Blueback charts remained popular until the late 19th century, when government subsidized organizations like the British Admiralty Hydrographic Office and the United States Coast Survey, began issuing their own superior charts on high quality paper that did not require reinforcement.