In conclusion, let me thank you most heartily for your kindness and
attention, and assure you that the honor I have had in addressing such
a distinguished audience, the pleasure I have had in presenting these
results to a gathering of so many able men--and among them also some
of those in whose work for many years past I have found enlightenment
and constant pleasure--I shall never forget.



[Transcriber's note: Corrected the following typesetting errors:
1) 'preceived' to 'perceived', page 16.
2) 'disharging' to 'discharging', page 30.
3) 'park' to 'spark', page 33.
4) 'pssition' to 'position', page 50.
5) 'to th opposite side' to 'to the opposite side', page 56.
6) 's resses' to 'stresses', page 147.]