The Library is also the place to see some of Murdoch Mackenzie’s beautiful charts of the water around Orkney. The wreck of the East Indiaman Svecia on North Ronaldsay’s Reefdyke in 1740 added to the case for greater aids to navigation in Orkney waters. The Earl of Morton called on Colin Maclaurin, one of the greatest mathematicians of the day, to take on the challenge of producing a comprehensive set of charts. Maclaurin, who was professor mathematics at Edinburgh University, was too busy – but he recommended a former student, who was not teaching at Kirkwall Grammar School. This was Murdoch Mackenzie.
Maclaurin was not only a great mathematician and an expert surveyor; he was also a leading advocate of the ideas of Sir Isaac Newton about gravitation – which included the motion of the tides. Even Galileo had not believed that the Moon was the cause, but Newton provided this mathematically. Maclaurin understood the new ideas of gravitation so well that Newton had offered to personally fund his position at Edinburgh. So Mackenzie had contact with the finest thinking of the time about tides and surveying and geometry, and he set about his work in a more systematic way than anyone had done before.
He started on the land, and when a hard winter froze the lochs of Stenness and Harray he went on the ice with a very long chain which formed his dead-level baseline. From this he built up a detailed map of the mainland of Orkney – and only then did he expand outwards to the sea and the islands and gather it all together into his first chart.
“For mariners, with its soundings and accompanying detailed sailing directions, it was revolutionary and remained the standard work until the modern admiralty chart,” write the distinguished modern geographer, Prof. Ronald Miller.
Murdoch Mackenzie’s charts are indeed works of precision and beauty, and you can see some of them and find out more about his story upstairs in the Archive section of the Orkney Library in Kirkwall.