Charting the life of the man who mapped Orkney
By Margaret Carr
(Story dated Monday, September 19, 2005)

Modern mariners have a North Ronaldsay shipwreck and an 18th century Kirkwall schoolmaster to thank for the accurate shipping charts used today.

The story of Orkney's own map man, Murdoch Mackenzie, was told in the BBC television programme Map Man, but here, Margaret Carr looks at the work of the father of hydrographic surveying.

Murdoch Mackenzie published the first properly surveyed charts of UK waters, funded entirely through his own efforts.

The charts were so good they were adopted by the Admiralty and used for almost a century.

Mackenzie was born in Kirkwall in 1712, third son of Kirkwall’s town clerk, James Mackenzie, who was also a notary public, a writer and Keeper of the Sasines. His mother was Marion Traill, of Tirlot.

The Mackenzie family owned Groundwater.

His father died in 1723 and Murdoch became friends with Kenneth and John McKenzie, who seem to have acted as his mentors.

When James Douglas, the 14th Earl of Morton, inherited the estates of Orkney in 1738, Murdoch Mackenzie was teaching at Kirkwall Grammar School.

Morton asked his friend, Colin Maclaurin, who was professor of mathematics at Edinburgh University, for advice on obtaining an accurate survey of Orkney, so he knew what he was getting.

Maclaurin recommended that his former pupils living in the area carry out surveys following his instructions.

It seems that Murdoch Mackenzie was probably a student at the university from 1729, though there is no record of him graduating.

Mathematics had only become a university subject about 1680 and arithmetic was not taught as widely as it is today. Surveyors were often provided with times tables so they could calculate areas. Professor Maclaurin knew that his former students had a proper grounding in maths and would be more likely to make accurate surveys.

Murdoch Mackenzie resigned from KGS in 1839. It is not clear what he did between then and 1842, but it is possible he assisted the Rev. Alexander Bryce, of Caithness, with his survey of the north coast of Scotland.

Certainly, by 1842 Mackenzie seemed to have some sort of surveying experience.

At the end of that year he announced his intention to raise subscriptions to carry out a survey of Orkney. He had a recommendation written by Professor Maclaurin.

He advertised in April and May, 1743:

“For the benefit and safety of navigation, the Orkney Islands are proposed to be exactly surveyed and navigate [sic] by subscription. All the rocks, shoals, soundings and courses of the tides will be justly marked and represented, several prospects of the land taken from the sea and directions given for sailing through the several channels and friths [sic]; with several other particulars as necessary to be known by sailors, but as yet entirely omitted in sea charts: so that a passage round the north coast of Britain which has hitherto been so dangerous and fatal to shipping may hereby be rendered both safe and convenient.

“Subscriptions will be taken in by the booksellers in Edinburgh; at whose shops, and at the coffee houses, a specimen and the proposals may be seen.”

The proposals said:

“How very serviceable it would be to a great Part of the trading Nations in Europe to have the Orkneys rightly navigate, will be obvious, from their Situation, to all acquainted with mercantile Business: and will also appear from the vast number of Ship-wrecks that happen there. On this small Island of N. Ronaldsha alone, about twenty British and Dutch vessels have been lost within the last 30 or 40 years many of them with very Valuable Cargoes, besides a much greater number on other Parts of that Coast; most of which might have been prevented by such a Chart of these Islands as is here proposed.”

In December, 1743, he went to London to seek support. Morton gave him help, including letters of introduction to several people. Contact was also made with the Danish and Dutch East India companies.

Murdoch Mackenzie received more than 50 subscriptions and promises of money while he was in London.

In July, 1744, he said he had received some surveying instruments from the Admiralty — a theodolite, a plane table and a chain. It was usual in those days for surveyors to use borrowed equipment because it was so expensive. The theodolite had only been invented in 1720.

The East India Company had advanced him £50 and two insurance companies had provided £15, a quarter of what they had agreed to pay him in total.

“I will proceed to Orkney, and hope, before winter, to make as much progress as will satisfy all concerned that the survey will be carried on as expeditiously as may be expected,” he wrote.

In all, he managed to raise 383 subscriptions, including 48 from London merchants, 44 from Scottish merchants, 16 from Rotterdam merchants, 11 from merchants elsewhere, 20 from seamen, five from trading and insurance companies, 17 from titled gentlemen, 36 from the gentry, five from lawyers, and 75 from Mackenzies.

Mackenzie estimated the survey would take four years.

He said he needed 12 men for sea and land service for five months of the year, at 3d a day; an assistant; money for ferries, freight and the hire of small boats; and two servants to prepare beacons on the land, all of which he estimated would cost £92 per year.

He also budgeted £90 for equipment, £20 for a large boat, £60 for a barque for one summer, and £100 for engraving the plates for the charts.

Murdoch Mackenzie was the first surveyor to recognise that sea charts could not be accurate unless the survey of the land was accurate. He wanted to provide sailors with points of reference so that by taking bearings on the land features they could see, navigators on ships could calculate exactly where they were.

The use of accurate measurements was very new.

The marine sextant did not undergo its first trials until 1757 and the marine chronometer, to help keep accurate time at sea (necessary for calculations using astronomical observations) was not developed until the 1760s.

Despite this, Mackenzie’s calculations of latitude were very close to the correct value.

Mackenzie said he would use trigonometry on the land and send boats to lie at the extremities of rocks and take bearings from the land.

To begin his accurate survey, he needed a base line.

A particularly cold winter proved a boon as the Loch of Stenness froze over.

This gave him a long, straight, level surface which could be measured accurately.

“Catching the opportunity of a very hard frost, poles were fixed in the ice in a straight Line, extending from the parish boundary Sandwick and Hara, to Broggar near the north-most Bridge, and lines or ropes stretched on the ice from pole to pole, along which was carefully measured, with an iron chain, the distance of three miles and three quarter,” he wrote later.

His workers erected beacons on hilltops to serve as points from which to establish bearings. Mackenzie’s maps also included other landmarks and big houses and other notable buildings.

In May, 1745, he returned to London to collect some of the promised money still owed and also intending to take out a patent over his charts.

By 1749 he was able to submit a paper to the Royal Society, The State of the Tides in Orkney.

In 1750, the charts were published as Orcades, or a geographical and hydrographical Survey of the Orkney and Lewis Islands.

It is not clear when he decided to include Lewis, and the general feeling was that this survey had been rushed and was not as accurate as the Orkney survey.

But the charts were far better than anything available before. Mackenzie introduced consistent symbols throughout the charts and some are still used today.

The Prime Meridian at Greenwich was not established officially until 1884, and Mackenzie had his meridian running straight through Kirkwall.

The Hudson Bay Company bought 30 copies of the Orcades charts.

The Admiralty was so impressed that Mackenzie was appointed Admiralty Surveyor to survey the entire west coast of Scotland, Ireland and the west coast of England and Wales as far south as Pembrokeshire. This led to the publication of A Nautical Description of the West Coast of Great Britain from the Bristol Channel to Cape Wrath, and A Nautical Description of the Coast of Ireland.

In 1760, A Chart of the Atlantic Ocean was published.

He published the standard work on hydrographic surveying, A Treatise on Maritime Surveying, in 1774 and the same year was elected a Fellow of the Royal Society.

The list of his proposers was headed by Joseph Banks and Daniel Solander, the two naturalists who sailed with Captain James Cook on his first voyage to the South Pacific. Other proposers included mathematician Patrick Murdoch, John Campbell, who had invented the sextant in 1757, and John Ibbetson, secretary of the Board of Longitude.

Mackenzie’s charts were the first to include depth information, but this was not exact enough. He invented the Station Pointer, a three-armed protractor still used in navigation throughout the world today, even though global positioning systems are in wide use. His coastal maps continued to be used by the Admiralty until the next full hydrographic survey in the 1840s.

Murdoch Mackenzie had no children, but he supported the next generation of his family. He financed the voyages of two nephews and took in his nephew, Kenneth, and his wife and eight children, to live with him in his home in Hampstead, London.

He also financed his nieces in legal battles over land.

Murdoch Mackenzie retired from the Admiralty in 1771, being succeeded by his nephew, Murdoch Mackenzie the younger, who was a naval officer. During his retirement, the elder Murdoch lived with the younger at his home in Minehead, Somerset, where he died in 1797.

Young Murdoch was the son of the elder Murdoch’s brother, Thomas. He was born in Kirkwall in 1743.

As a midshipman aboard HMS Dolphin he had been part of John Byron’s circumnavigation of the globe in 1764-66.

As Admiralty Surveyor he was responsible for surveying the south coast of England and the Isle of Wight. He reached the rank of Commander in 1814.

Unfortunately, his deteriorating eyesight meant he had to retire from the post in 1788.

Murdoch Mackenzie the younger died in Minehead in 1829.

A cousin, Graeme Spence, was apprenticed to the younger Murdoch at the age of 15. Two years later he became the official assistant to the head surveyor at the Admiralty and eventually succeeded to the post on his cousin’s retirement.

From 1789 to 1793, Spence undertook a massive and detailed maritime survey of the Isles of Scilly and the approaches. His work is still recognised as setting a fresh standard and still forms the basis for charts of these isles.

Graeme Spence also had a long-lasting effect on Orkney. He was the person who first proposed that Scapa Flow would make an ideal naval base.

Longhope became the official assembly point for convoys assembled to protect the British trade routes with the Baltic during the Napoleonic wars and the two Martello towers were built to guard the entrance. However, they were not finished until 1814, by which time the need had passed.

Graeme Spence died in 1812.

The Admiralty Hydrographic Office was established in Somerset in 1795 as a direct result of the work of these three Orcadians.

There is a still a link between Orkney and the UK’s hydrographic surveys today. The navy has used boats chartered from Orkney company Reid Marine for the survey work for more than 20 years.