AIRY TELLS THE TRUTH

QUIZ QUESTION: What was it, according to Sir David Brewster, ‘' ... which no Englishman can peruse without unmingled pain’? (North British Review 1847 7, p226)

ANSWER: Airy’s letter to Leverrier of October 21st, 1846 .

Airy wrote to Leverrier on the 14th of October congratulating him, ‘You are to recognized beyond doubt as the real predictor of the planet’s place,’ then added a week later on the 21st:

‘no person in England will dispute the completeness of your investigations, the sagacity of your remarks on the points it was important to observe, and the fairness of your moral convictions as to the accuracy and certainty of the results. With these things we have nothing which we can put in competition. My acknowledgement of this will never be wanting; nor, I am confident, will that of any other Englishman who really knows the history of the matter.’

Airy did really know the history of the matter. This letter was (naturally enough) soon printed in Comptes Rendues by Arago, at which Airy complained (letter to Arago, 26th). However, he was the Astronomer Royal. He suffered much from the publication of this letter.

A month later, in his address to the RAS (Nov. 13th) Airy compared Leverrier to Copernicus:

'since Copernicus ... nothing (in my opinion) so bold, and so justifiably bold, has been uttered in astronomical prediction. It is here, if I mistake not, that we see a character far superior to that of the able, or enterprising, or industrious mathematician; it is here that we see the philosopher. The mathematical investigations will doubtless be published in detail and they will, as mathematical studies, be highly instructive; but no details published after the planet's discovery can ever have for me the charm which I have found in this abstract [Leverrier's memoir] which preceded the discovery.'

A stark contrast is here made with Adams as the mere 'industrious mathematician' who only published his results after the discovery. Of this presentation Smart (amongst others) complained, ‘Airy’s account contained several extraordinary passages, full of the liveliest admiration for LeVerrier and almost completely destitute of but the barest recognition of Adams’ achievement’ (p68). However, Smart reassured his readers, the verdict of history had been ‘far different.’

One might have expected the British people to accept the firm and twice-stated views of their own Astronomer Royal upon this subject, but, alas, they did not - far from it. Airy was severely castigated on all sides, such that the Neptune affair 'seemed unduly to overshadow him for the rest of his life’ (W.Ellis, The Observatory 1905 28 p.184). His six-hundred page autobiography contained only one (bitter) paragraph about Neptune! For more on Airy's candid opinion see "Airy Blows His Top".

Hatching the Plot

Francois Arago, director of the Paris Observatory, had the highest respect for Airy's integrity. 'Ceux qui connaissent M.Airy n'eleveront certainement aucun doute sur la verite de sa declaration' (Comptes Rendues 19 Oct 1846, p.752): 'Those who know Mr Airy cannot harbour any doubt over the veracity of his word.' Thereby Arago argued against the British case, and used Airy’s letter to Leverrier on June 26th in this context. From this letter it appeared quite evident that its author Airy had no clue about how Uranus' distance ('radius vector') would be affected by an unknown planet's perturbation, and Leverrier had to explain the matter to him. This was the first English response to Leverrier's June prediction. Airy was, as Arago explained, one of the most highly informed persons on the subject of celestial mechanics; and, after all, supposedly had Adams' prediction ‘in his hand’. Arago was thereby resting the entire French case upon Airy's integrity. In this, he went too far.

In their commendible account of events Baum and Sheenan state, 'Airy's actions or inactions, with which one can sympathise up to this point, now become somewhat inscrutable' (1997, p.99). Likewise, Turner in 1904 had experienced a 'difficulty in understanding Airy's conduct' at this point (p.62). Airy was, quite simply, plotting, to secure the planet for England.

Airy's Portrait courtesy Royal Astronomical Society