the instantaneous pole will separate from the axis of the instrument,
and the axis will incline more and more till the spinning can no
longer go on, on account of the obliquity. It is easy to see that, by
attending to the laws of motion, we may produce any of the above
effects at pleasure, and illustrate many different propositions by
means of the same instrument.

* _Transactions of the Royal Scottish Society of Arts_, 1855.

***
Address to the Mathematical and Physical Sections of the British
Association.

James Clerk Maxwell


[From the _British Association Report_, Vol. XL.]

[Liverpool, _September_ 15, 1870.]


At several of the recent Meetings of the British Association the
varied and important business of the Mathematical and Physical Section
has been introduced by an Address, the subject of which has been left
to the selection of the President for the time being. The perplexing
duty of choosing a subject has not, however, fallen to me.

Professor Sylvester, the President of Section A at the Exeter Meeting,
gave us a noble vindication of pure mathematics by laying bare, as it
were, the very working of the mathematical mind, and setting before