Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: The Mapmakers--I need more!
    From: George Huxtable
    Date: 2002 Dec 9, 00:27 +0000

    Trevor Kenchington, writing about a 1770 chart of Nantucket Sound, said-
    
    >That chart was likely from the "American Neptune", the result of
    >DesBarres' surveys. There are quite a number of bound copies of the
    >Neptune around, plus many loose charts. Although a lot of them are held
    >by public institutions, others are in private hands and appear on the
    >market from time to time. The great prize is often considered to be
    >Desbarres' chart of Sable Island, though it is some 8 feet long, which
    >makes it a bit hard to display!
    >
    >A couple of years back, I ran into a history student who was writing a
    >PhD thesis on DesBarres and his survey methods. He claimed, though I do
    >not know how seriously, that DesBarres trained Cook in surveying, which
    >would have to be counted quite an achievement even if Cook went on to
    >exceed his mentor's capabilities.
    >
    >DesBarres was a military engineer, of Swiss origins, who was trained in
    >mathematics and engineering at Woolwich in the early 1750s. His first
    >chart, based on French materials captured in Louisbourg, was prepared in
    >1759 and covered the St.Lawrence. Thus, along with Cook, he made
    >possible the conquest of Quebec and New France by providing the English
    >fleet with the information needed if it was to work up the river. Since
    >the great flowering of hydrographic surveying dates from about that
    >time, I have supposed (without much supporting evidence) that its
    >origins lay in the terrestrial survey methods which DesBarres and other
    >engineers took to sea. If so, those methods had been developed early in
    >the 17th century, when the increasing firepower of artillery drove
    >fortress builders to a new level of sophisticated, mathematical design
    >and their opponents to a matching level of sophistication in the layout
    >of siege works.
    >
    >As to the methods actually used: DesBarres left one account of his own
    >methods, with comments on measuring out a baseline on shore, then using
    >theodolites and plane tables to map the coastline. Copies of that were
    >provided to a sloop (i.e. a small warship, not a sloop-rigged boat)
    >which beat on and off the shore to a distance of ten miles or so, taking
    >soundings, to a "shallop" which did the same around headlands and
    >islands, and to "boats" which worked the "indraught" to the heads of the
    >bays. He did not remark on the instruments used on the sloop, shallop
    >and boats but I'd guess a leadline and quadrants used for horizontal
    >angles. They apparently also laid a 100-fathom line taught across the
    >bottom to give themselves a measured baseline in the water.
    >
    >Where his crews took the time to get it right, DesBarres surveys are
    >about as accurate (though not as detailed) as mid-20th century ones.
    >However, I know of points on the Nova Scotian coast where the complexity
    >of the rocky shoreline seems to have overwhelmed the survey parties,
    >resulting in substantial errors such as an entire headland being missed
    >and the coves on either side run together.
    >
    >One further point: The Admiralty commissioned the surveys of the
    >American coastline, so far as I can tell, before much of England was
    >properly charted. Why? My guess is that they had traditionally-trained
    >pilots who knew the English coast without needing charts, whereas ships'
    >Masters needed to navigate along American coasts that they had never
    >seen before and without the aid of people who knew every rock and
    >channel by heart. Hence, modern concepts of paper-based navigation were
    >needed on the unknown coast, in place of the memory-based pilotage that
    >had served mankind for millenia.
    >
    >
    >Trevor Kenchington
    =================
    
    Response from George Huxtable.
    
    I can fill in a few gaps in that story, not much from my own knowledge, but
    mainly from my copies of J C Beaglehole's definitive "Life of Captain James
    Cook", pub. Hakluyt Society 1974 (and also by A&C Black), and G S Ritchie's
    "The Admiralty Chart" (Hollis & Carter 1967).
    
    Ritchie refers to "Des Barres' Atlantic Neptune", and I wonder if this is
    the same work as the "American Neptune" discussed by Trevor. Ritchie points
    out that although that title refers to DesBarres only, it was in fact a
    compilation of the works of many men-
    Cook, and his successor Michael Lane, in Newfoundland;
    Holland in the River St.Lawrence, Prince Edward Island and Cape Breton
    Island, the coasts of Maine and New Hampshire;
    DesBarres himself on the coasts of Nova Scotia and New Brunswick and Sable
    Island;
    Lieut. Hurd from St John to Passamaquoddy Bay;
    George Gauld as far south as Florida and even in the West Indies.
    
    Ritchie adds that DesBarres gave too little credit to the many surveyors
    whose work he published, and made good money privately from its sale.
    
    His career included a spell as Governor of Cape Breton Island, and he must
    have been quite a character: reported as dancing on a table on his 100th
    birthday!
    
    Cook first learned about plane-table surveying from another military man,
    Samuel Holland (not surprisingly, a Dutchman) who had been commisioned into
    the British Army. Holland later became surveyor-general of Quebec. Holland,
    and also Cook and John Simcoe (master and captain of the Pembroke)
    overwintered in Halifax, Nova Scotia, in 1758-9, as also did Des Barres.
    Ritchie records that these four spent many sessions discussing surveying
    together over that winter, so both Holland and DesBarres could have
    contributed to Cook's education on surveying mattersBeaglehole doesn't
    mention DesBarres, in that context
    
    Cook and Holland, under Simcoe, subsequently made surveys together,
    culminating in Cook's own survey, using ship's boats, of the upper St
    Lawrence, which allowed the passage of British ships to capture Quebec from
    the French. Afterwards, the French Governor said "The enemy have passed 60
    ships of war where we dare not risk a vessel of 100 tons by night or day."
    
    Later, Cook tranferred to the Northumberland, as master, and was in St
    Johns, Newfoundland, in September/October 1761. Cook accompanied Desbarres
    to the island of Carbonera. Desbarres surveyed the island and drew up a
    plan for new fortification. Cook made a draught of Harbour Grace, and the
    Bay of Carbonera. Cook and Desbarres must have been in close contact over
    this period, and Desbarres may indeed have passed some of his knowledge
    over to Cook, and perhaps vice versa also. By that time, Cook was already a
    more-than-competent surveyor both on land and at sea, so at that meeting he
    would have little to learn from DesBarres..
    
    Desbarres, however, seems to have acquired a poor reputation at the
    Admiralty. Beaglehole quotes two Admiralty surveyors, 70 and 100 years
    later, saying of the charts of that region of North America that "most of
    them were a danger to seamem: throw away Desbarres and the rest. Two only
    could be trusted- Cook, and Lane."
    
    Beaglehole adds: "But perfection is granted to no man, and there were minor
    dangers hidden from Cook".
    
    Cook's surveying of Newfoundland had continued in 1764 to 67 in his own
    command, the schooner Grenville, with Lane as his assistant, and Lane
    completed the work after Cook was taken away for circumnavigation duty.
    
    ======================================
    
    Trevor's guess is, I think, rather wide of the mark, when he says-
    >The Admiralty commissioned the surveys of the
    >American coastline, so far as I can tell, before much of England was
    >properly charted. Why? My guess is that they had traditionally-trained
    >pilots who knew the English coast without needing charts, whereas ships'
    >Masters needed to navigate along American coasts that they had never
    >seen before and without the aid of people who knew every rock and
    >channel by heart.
    
    There were indeed charts of Englich coastal waters, long before that date,
    though perhaps far below Cook's meticulous standard. The difference is that
    these were commercial charts, not commisioned by the Admiralty, and not in
    general made by naval vessels. Many were copied, or stolen from older Dutch
    "platts", as the Dutch were the first real chart-makers.
    
    Captain Greenville Collins was appointed Hydrographer-in-ordinary to the
    King by Charles II in 1682 to survey the coasts of Great Britain, and
    published his collection of charts as "Great Britain's Coasting Pilot" in
    1693. I have a reduced facsimile copy of the 1753 edition (and I wonder
    whether these charts had been updated much on the original ones). It
    contains 48 charts in various sizes, scales, and orientations, together
    with sailing directions, tidal information, and some coastal silhouettes.
    Only a few of the charts shows a scale of latitude, and none show
    longitude: nevertheless, this must have been an essential documents to
    carry aboard ship, for those that could afford it.
    
    Perhaps those in a regular trade, such as the North Sea Coal Trade, got to
    know the waters well enough that they were content to do without a chart,
    as their forefathers had done. When I am sailing in familiar waters, I
    seldom need to look at my local charts, though they are always out of the
    locker. But  a sailing vessel, particularly a square-rigger, might at any
    time be driven out of her home waters by adverse weather. A returning
    trader might get orders to unload at a port unfamiliar to her master.
    Charts would be of great value then.
    
    Note that Collins was Hydrographer to the King, not Hydrographer of the
    Navy; an important difference. The navy post commenced with Dalrymple as
    late as 1795. Naval Officers were expected to acquire their own charts
    wherever they could. Admiralty Charts didn't exist. Cook's charts of
    Newfoundland were privately published for him.
    
    In 1751 the Admiralty employed Murdoch Mackenzie, and later his nephew of
    the same name, as their surveyors, to produce charts of the west coasts of
    Britain and Ireland. These famous charts were made in the period 1751 to
    about 1780.
    
    So I reckon that the state of charting of British waters in the period that
    Trevor refers to, was not as bleak as he makes out.
    
    I think the answer to Trevor's question lies with the French, who had just
    been expelled from North America, except for some islands in the St
    Lawrence. French influence in those islands, and to a lesser extent in
    other French-speaking provinces of Canada, exists to this day. The
    Admiralty's need for good charting was to forestall any French re-invasion,
    as France and Britain were in a perpetual state of on-and-off war. Perhaps
    (I suggest) these coastal regions of Canada were so lightly populated, with
    so little trade except the cod fishing, that there was no prospect of
    commercial surveying and chartmaking. That was why Cook was sent out in a
    Naval vessel, to do that job.
    
    But I am no historian, so you should take what I say with a pinch of salt.
    
    George.
    
    ------------------------------
    
    george---.u-net.com
    George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    Tel. 01865 820222 or (int.) +44 1865 820222.
    ------------------------------
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site