Life and Scientific Work of Peter Guthrie Tait - School of Mathematics ...

egularity ; and
SIR WILLIAM THOMSON 31
on the morning following the Monday evening meetings
paid a visit to Tait's Laboratory immediately
after the conclusion of Tait's
lecture. It was then that we laboratory "veterans" had an opportunity
of coming into closer touch with the great Natural Philosopher, who
would occasionally pass round the laboratory and inspect the experiments
which were in progress. Most instructive discussions would at times
arise, Kelvin's mind branching off into some line of thought suggested
by, but not really intimately connected with, the experiment. At other
times the conversation between Kelvin and Tait turned on the papers
which had been communicated the evening before. I remember a lively
discussion arising on the statistical effect of light impressions on the
eye. The argument was reminiscent of the old tale of the two knights
and the shield ; for while Tait was laying stress on the time average,
Thomson was looking at it from the point of view of the space average.
For many years Tait's successive assistants reported the Meetings of
the Royal Society to Nature ;
and
this duty fell to me during the years
1879-83. At one of these meetings Sir William, as he then was, had in
his well-known discursive but infinitely suggestive manner so talked round
the subject of the communication that I had some difficulty in quite under-
standing its real essence. Next morning I tried to get enlightenment from
Tait. He laughed and said " I had rather not risk it ; but the great man is
coming at twelve— better tackle him himself." When in due time Sir William
was "tackled," he fixed his gaze at infinity for a few moments and then,
a happy thought striking him, he said, with a quick gesture betokening
release from burden, " Oh, I'll tell you what you should do. Just
wait till
the Nature Report is published — that fellow always reports me well." Tait's
merriment was immense as he unfolded the situation, and he chaffed
Thomson as to his obvious inability to explain his own meaning. Not a
few of both Kelvin's and Tait's communications to the Royal Society of
Edinburgh were never written out by them ;
in the columns of Nature.
they appear as reports only
Another scene, in which Thomson and Tait were the main agents, rises
in the memory. Once on a Saturday morning in summer when two of
us were working with electrometer and galvanometer in the Class room
Tait arrived in some excitement and said " Thomson will be here in half
an hour on his way to London. He wishes to try some experiments with
our Gramme machine and will need your cooperation with electrometer