[Footnote 1: Investigations respecting coreless vortices will be found in a
paper by the author, "Vibrations of a Columnar Vortex," _Proc_. R.S.E.,
March 1, 1880; and a paper by Hicks, recently read before the Royal
Society.]

[Footnote 2: See papers by the author "On Vortex Motion." _Trans_. R.S.E.
April, 1867, and "Vortex Statics," _Proc_. R.S.E. December, 1875; also a
paper by J.J. Thomson, B.A., "On the Vibrations of a Vortex Ring," _Trans_.
R.S. December, 1881, and his valuable book on "Vortex Motion."]

As a step toward kinetic theory of matter, it is certainly most interesting
to remark that in the quasi-elasticity, elasticity looking like that of an
India-rubber band, which we see in a vibrating smoke-ring launched from an
elliptic aperture, or in two smoke-rings which were circular, but which
have become deformed from circularity by mutual collision, we have in
reality a virtual elasticity in matter devoid of elasticity, and even
devoid of rigidity, the virtual elasticity being due to motion, and
generated by the generation of motion.

* * * * *




APPLICATION OF ELECTRICITY TO TRAMWAYS.

By M. HOLROYD SMITH.


Last year, when I had the pleasure of reading a paper before you on my new