Item 49 - Letter from George Airy

4 pp.

Royal Observatory Greenwich - WW is in Augustus De Morgan's 'collection of Authorities for the History of Science...in one of the early pages'. GA has had a large amount of observations made around Ireland (twenty-eight stations): 'Of course the reduction in the way in which I wish to reduce them will be a formidable work'. GA gives Cubitt's rule for blowing down chalk [see GA to WW, 24 February 1843]. WW is not attaching the names of 'Clairaut, D. Besneulli, &c...to the proper part of the subject. The equilibrium-theory as a statical theory of quiescent fluid, is very good (the proof of elliptic form &c being excellent, though the mere combination of effects of two bodies and the laws of the compound result are very simple). And I do not call the theory contemptible in itself, but as applied to the tides'. Abstractly the equilibrium theory is very good while Laplaces's is only admissable. As applied the equilibrium theory is absurd and Laplace's theory is very imperfect.: 'As to your opinion that Laplace's theory is not in the right direction because it does not at once give limits in longitude, I think that you have not sufficiently considered the order in which all results founded on differential equations proceed'. 'As to the combination of equilibrium theory with that of waves, I repudiate it absolutely... The failure of Laplace's on wave theory is merely one of mathematics and will, I hope, be conquered in time'.