of the University Press for assistance in
publishing the work; and they agreed to give me paper and printing for
500 copies. This notice was received from Professor Turton on
Nov. 29th, 1825. It was probably also in this year that I drew up an
imperfect 'Review' of Coddington's Optics, a work which deserved
severe censure: my review was never finished.

"In the Long Vacation at Keswick I had six pupils at _L42_ each. In
the October term I had Marshman and Ogilby at _L105_ for three terms,
and Dobbs at _L75_ for three terms. I had, at Mr Peacock's suggestion,
raised my rate from 60 to 100 guineas for three terms: this prevented
some from applying to me, and induced some to withdraw who had been
connected with me: but it did me no real hurt, for engrossment by
pupils is the worst of all things that can happen to a man who hopes
to distinguish himself. On Dec. 17th I went to Bury, and returned to
Cambridge on Jan. 30th, 1826.

"I have the attendance-bills of my Lectures to Senior Sophs (16) from
Feb. 3rd to Feb. 23rd, and to Freshmen (40) from Feb. 27th to
Mar. 15. It would appear that I gave but one college-lecture per day
(my belief was that I always had two). The tutor's stipend per term
was _L50_. On my quires I find, Investigations for the ellipticity of
a heterogeneous spheroid when the density is expressed by sin
_qc_/_qc_ (the remarkable properties of which I believe I discovered
entirely myself, although they had been discovered by other persons),
Theoretical Numbers for precession, nutation, &c., some investigations
using Laplace's Y, hard work on the Figure of the Earth to the 2nd
order,'Woodhouse's remaining apparatus,' Notes about Lambton's and
Kater's errors, Depolarization, Notes of Papers on depolarization in
the Phil. Trans., Magnetic Investigations for Lieut. Foster,
Isochronous Oscillations in a resisting medium, Observations on a
strange piece of Iceland Spar. On Mar. 7th forwarded Preface and Title
Page for my Mathematical Tracts.

"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. My first notion
was simply to try the rate of a clock, and the Ecton mine was first
thought of. I made enquiries about the Ecton mine through Mr Smith (of
Edensor), and visited the mine, but in the meantime Whewell had made
enquiries in London and found (principally from Dr Paris) that t