other and very effective agencies at
work here to produce electric excitement. The actual _bocca_ of the
volcanic vent whence the steam roars off constitute the cone a veritable
hydro-electric machine. Mechanical energy in various forms is
transformed into electric energy. Chemical action is going on both in
the solid and in the vapourous and gaseous emanations as they rush into
and remain in the air or descend from it, and chemical action is
transformed in part into electric energy. Percussion between ascending
and descending particles and fragments, fractures and breaking up of
more or less of these, thus and by sudden changes of temperature in
cooling, are likewise operative. In addition, great and violent
movements in the atmosphere itself result from the large local
accessions of temperature by the heated volume driven up into it, and
which in turn give rise to electric disturbance of the same character as
those produced in wind storms and whirlwinds, brought about by the
natural causes which every day effect disturbances in our atmosphere all
over the globe.

[7] (P. 135). The views stated in note 3 (to page 96) may here again be
referred to as in point. How is it possible, in the present state of
science at least, to establish any physical connection between an
eruption in Java and one of Vesuvius, "with half the world between,"
when not even having the solitary connecting link of complete
contemporaneity, and which, if it existed, yet might be nothing but
accidental? A list of shocks upon record, which have occurred more or
less nearly simultaneously at distant parts of the world, may be found
in my fourth Report, ("Facts of Earthquakes," "British Association
Reports, 1858") and the reasons are there given for rejecting the notion
of any direct physical connection between the origins of the respective
shocks.

Shocks, emanating from the close neighbourhood of volcanic vents, or
simultaneity of eruption, in vents not far distant from each other,
stand upon a different footing.

Transcriber's Notes.

Preserved the unusual, but consistent, spelling of "develope."

Preserved the unusual, and inconsistent, references to the Plates.
Sometimes Arabic numerals are used, but usually Roman numerals. Most
have "A" attached to the name (which was changed to "a" to avoid
confusion in the Roman numerals), but not VIII, and sometimes not in the
references to them.

Equations were converted to linear text, adding