Last week, Nevil Maskelyne (1732-1811) hit the big time, or rather his stripy, padded Indian silk observing suit did, in an article in the Guardian by Maev Kennedy. Maskelyne was Astronomer Royal from 1765 until his death in 1811, meaning that he was, ex officio, a Commissioner of Longitude. As well as this he is, of course, particularly important to our story as someone who was involved in testing means of finding or keeping longitude during sea voyages to St Helena and Barbados: Tobias Mayer's lunar tables and Harrison's H4 timekeeper. Maskelyne was also founder and editor of the Nautical Almanac, which made the lunar distance method a practical means of finding longitude at sea.

For readers of Dava Sobel's Longitude, Maskelyne is also the villain of the piece. He is charged with opposing Harrison, largely so that he could win the prize himself. This is not the place to go into this here, but suffice to say that it misunderstands the nature of 'the prize', who was entitled to win it and the very real problems of using and replicating Harrison's timekeeper. This blog, and talks by members of the team and others over the course of this year, will, I hope, begin to flesh out and correct such views. We are taking advantage of the fact that 2011 is the bicentenary of Maskelyne's death and, perhaps more cheerfully, the 250th anniversary of his voyage to St Helena (for the purpose of observing the 1761 transit of Venus, as well as testing the lunar distance method of longitude determination). We are also celebrating the recent acquisition of an important collection of items relating to Maskelyne, his wife Sophia and daughter Margaret.

The journals, letters, portraits, items of clothing and other objects combine to give us a fuller picture of life at the Observatory in the 18th and early 19th century, and of Maskelyne himself, but the star object is surely the observing suit. The shorter print version of the Guardian article included an image of the suit being carefully held by two curators and a conservator (the online version only gives a fairly stock image of the Royal Observatory, Maskelyne's home and workplace of 46 years). Copyright means that I can't freely reproduce the image here, but it seems only fair that interested online readers should be able to get an idea of this remarkable item. So, here is an image of a former NMM curator, David W. Waters (known as Willie Waters), actually wearing the thing. I hasten to add that it was then in private hands and that curators would emphatically NOT DO THIS KIND OF THING now.

This picture does not quite do justice to the large, well-worn and padded seat of the trousers: Maskelyne was probably a reasonably plump man and clearly did a lot of sitting down at his instruments. We do know that Willie Waters was not particularly tall - perhaps 5' 6" - and Amy Miller, our Curator of Decorative Arts, assures me that the cut of the suit shows that Waters was taller than Maskelyne. She has also explained what a peculiar garment it was, and what a strange sight Maskelyne would have made, walking across the Observatory's courtyard, presumably in wooden pattens to keep his padded feet out of the mud, to the meridian instruments.

We hope that the suit and other items from the Maskelyne collection will be on view to delegates to our forthcoming symposium on Maskelyne on Saturday 15 October 2011 (probably as a specially arranged visit to the conservation studios the day before). Speakers will include members of the Longitude Project team, NMM curators as well as Jim Bennett, from the Oxford Museum of the History of Science, and Mary Croarken, who has published extensively on Maskelyne, his assistants and early scientific computing. More details of the programme will be available on the website in due course.

Further reading

- Mary Croarken, 'Providing longitude for all: the eighteenth-century computers of the Nautical Almanac', Journal for Maritime Research (2002) - free online
- Derek Howse, Nevil Maskelyne: the Seaman's Astronomer (Cambridge University Press, 1989)
- Nicky Reeves, '"To demonstrate the exactness of the instrument": Mountainside Trials of Precision in Scotland, 1774', Science in Context 22 (2009), 323-340 [Abstract]