SIR,May I put in a mild caveat against excessive indulgence in potato-cakes, based on an experience in my undergraduate days at Trinity College, Cambridge, when WHEWELL was Master?

WHEWELL was a man of robust physique and hearty appetite, and I noted that he ate no fewer than thirteen, considerably more than half the total.

I think that I did not become acquainted with Mr Whewell till the next term, when I met him at a breakfast party at Mr Peacock's.

I shewed my paper on sqrt(-1) to Mr Peacock, who was much pleased with it and shewed it to Mr Whewell and others.

one on the Figure of the Earth and Tides; and at some other time one on the motion of a body round two centers of force; both from Mr Whewell.

The most active man in this suppression was Mr Whewell: its date must have been near to 1830.

Whewell's Mechanics (1819) contains a few and easy applications of the Differential Calculus.

The books on applied Mathematics were Wood's Mechanics, Whewell's Mechanics, Wood's Optics, Vince's Hydrostatics, Vince's Astronomy, Woodhouse's Plane Astronomy (perhaps rather later), The First Book of Newton's Principia: I do not remember any others.

Mr Peacock or Mr Whewell had some time previously applied to me to write a Paper on Trigonometry for the Encyclopaedia Metropolitana, and I had been collecting some materials (especially in regard to its history) at every visit to London, where I read sometimes at the British Museum: also in the Cambridge libraries.

"Some time in this term I began to think of the possibility of observing the diminution of gravity in a deep mine, and communicated with Whewell, who was disposed to join in experiments.

On May 24th Whewell arrived, and we took a pendulum and clock down, and on the 30th commenced the observation of coincidences in earnest.

I slipped this into Whewell's door.

While there I heard from Whewell that Woodhouse was dead.

"Before the beginning of 1828 Whewell and I had determined on repeating the Dolcoath experiments.

Invitations had been received, and everything was arranged with Whewell.

On the 19th I sent the instruments up, for the water was near our station, and Sedgwick, Whewell, and I went on a geological expedition to the Lizard.

On another occasion Sedgwick, Whewell, and I had a capital geological expedition to Trewavas Head to examine granite veins.

Whewell saw my draft and drew up a much more pithy one, which I adopted and sent to the Philosophical Magazine.

His friendship with Whewell was very close.

Although Whewell was at times hasty, and rough-mannered, and even extremely rude, yet he was generous and large-minded, and thoroughly upright.

In power of mind, in pursuits, and interests, Airy had more in common with Whewell than with any other of his friends.

It was with Whewell that he undertook the experiments at Dolcoath: it was to Whewell that he first communicated the result of his remarkable investigation of the Long Inequality of Venus and the Earth; and some of his Optical researches were conducted jointly with Whewell.

Whewell took his degree in 1816, seven years before Airy, and his reputation, both for mathematical and all-round knowledge, was extremely and deservedly great, but he was always most generous in his recognition of Airy's powers.

" Their close intercourse was naturally interrupted by Airy's removal to Greenwich, but their friendly feelings and mutual respect continued without material break till Whewell's death.

Whewell died on Mar. 6th, 1866, from the effects of a fall from his horse, and the following extract is from a letter written by Airy to Whewell's niece, Mrs Sumner Gibson, on hearing of the death of his old friend: "The Master was, I believe, my oldest surviving friend (beyond my own family), and, after an acquaintance of 46 years, I must have been one of his oldest friends.