Meridians and Makers
I’m looking back to research that began around 2010, I didn’t know it would ever come to anything, I was house sitting for friends up in the North East and took a day trip to Banff, in the museum I came across the intriguing object below.
This is an Astronomical Rotula, which looks like a roughly circular sheet of paper with dense statistical information about the sun and moon laid out radially and concentrically, it appears to have a layer that can be moved independently around the centre, which has holes punched in it to help rotate it. In the museum there is a display about James Ferguson, Fellow of the Royal Society, he was born in 1710 near Rothiemay, he was an improver of astronomical and other scientific apparatus. I didn’t do anything with this image, but several years later after reading Dava Sobel’s Longitude I got interested in pocket globes and this led me to find one made by Ferguson in the collection of the National Museum of Scotland.
While writing this I came across a version of the Astronomical Rotula sold by Bonhams in 2022.
Here’s what they said about it:
The Astronomical Rotula Shewing the Change and Age of the Moon, the Motion of the Sun, Moon and Nodes, with all the Solar and Lunar Eclipses, 5 sheets engraved by J. Mynde after Ferguson, comprising 4 volvelles over a circular scale, working with central thread intact, cut square to size of scale sheet (just within platemark on sides, not touching printed area), slightly frayed at margins, 320 x 320mm., c.1739
With the footnote:
SCARCE “ASTRONOMICAL ROTULA” invented and designed by the Scottish scientific instrument maker James Ferguson (1710–1776). Designed to demonstrate the motions and positions of the sun and moon, including the dates when the moon’s path crossed the earth’s orbital plane and hence the dates of solar and lunar eclipses. Ferguson had “sent a description to Professor Colin Maclaurin, who suggested a slight correction and volunteered to organize a subscription to enable it to be engraved and published” (ODNB). It is calculated to show the days of all the new and full moons from the years 1752 until 1800.
Apparently this pocket globe made around 1750 shows the route of George Anson’s circumnavigation between 1740 and 1744. It’s from the earliest edition, later ones show James Cook’s circumnavigations.
I managed to track down a biography of Ferguson on BIBLIO’s New Zealand website:
James Ferguson (1710-1776) was a Scottish autodidact who settled in London after a peripatetic life involving spells as a shepherd, miller, engineer, astronomer and lecturer. In his autobiography, he claims that, at the age of 20, he “made a globe in three weeks at my father’s, having turned the ball thereof out of a piece of wood, which ball I covered with paper, and delineated a map of the world upon it made the meridian ring and horizon of wood covered them with paper, and graduated them” (Ferguson, p.21). In 1755, he purchased the vast majority of the plates and instruments previously owned by John Senex, a leading producer of pocket globe. Ferguson subsequently designed his own pocket globe and produced several editions, but in 1757 he sold his business to Benjamin Martin, overwhelmed by his numerous responsibilities. Ferguson is most widely- known as a remarkable example of self-education, and for his production of scientific instruments and apparatus, notably orreries...
James Ferguson, Life of James Ferguson, F.R.S. (Cambridge: Cambridge University Press, 2010); John Millburn, Wheelwright of the Heavens. The Life and Work of James Ferguson (London, 1988).
The work that I made heavily drew on my research at the National Museum of Scotland, initially I contacted Dr Alison Morrison-Low who was about to retire, she advised regarding what I could look at in the collection and reading material that would be relevant, but it was Julie Orford, at that time the Assistant Curator of Science who showed me objects in the NMS Granton stores. I am indebted to them both for their generosity.
Below my work in progress, and the resulting work Light Meter.
