This chart was printed using copperplates and the painstaking process of engraving the plates for this chart has been achieved in the same ‘style’ as a number of other Des Barres publications held in the Heritage Charts collection: A113, A114, A115, A208, A401.  The original document was stored folded for several hundred years, and the staining on the chart is the imprint of the ink on the folded page.

As with all the other Des Barres’s publications, land relief is shown through hachuring and includes much detail about settlements, land division, buildings and roads.  The soundings are all concentrated around the major inlets and harbors which may have had significance at the time or had potential as shelter for British shipping.  By 1770 the British were looking for safe harbors for their fleet anywhere between New York and Halifax.

Casco Bay contains a great number of islands, and most if not all are faithfully recorded by Des Barres on this chart. A popular myth is that there are enough islands for every day of the year, hence they are sometimes called ‘the calendar islands’   In reality there are less than two hundred of them, but still more than enough to challenge even the best of mariners.

It should be noted that amongst the place names which appear on the chart is that of Falmouth which today is known as Portland.  In the early days of the Revolutionary War, in May 1775 when the British army was under siege in Boston, local Patriots in Falmouth captured several ships carrying supplies for Boston and weaponry from Fort Pownall at the mouth of the river. 

The British Vice-Admiral, Samuel Graves, then in charge of the Royal Navy supply chain to the troops in Boston, was under orders from his superiors (issued in July 1775 and received by him on October 4) to ‘carry on such Operations upon the Sea Coasts ... as you shall judge most effective for suppressing ... the Rebellion.’  Vice Admiral Graves ordered Captain Mowat to ‘lay waste burn and destroy such Sea Port towns as are accessible to His Majesty's ships...’  Mowat, Commander of HMS Canceaux, being by all accounts an amiable fellow, drafted a letter to the people of Falmouth (now Portland) warning them of what was about to befall them, and offering refuge for British Loyalists.

The aftermath of the raid proved very expensive for the British.  400 buildings and houses were destroyed or damaged, in the harbor eleven small vessels were destroyed and four captured, and one man was killed and one wounded.  Although very few direct casualties were reported the townsfolk were left to fend for themselves for the winter, with no lodging, eating or housekeeping to be had in the town.  The overall cost of the loss was put at about £50,000.  News of the raid was met with outrage by Congress who resolved a recommendation that all provinces declare themselves self-governing and independent of British rule or influence, and that plans for a Continental Navy be advanced.   Propagandists had a field-day citing cruelty and The Massachusetts Provincial Congress authorized the licensing of privateer actions against the British Navy, which was to be a thorn in the side of the British for years to come.  The careers of both Graves and Mowat suffered as a consequence of the action.