  Lord Kelvin (William Thomson) made important contributions to the study of
atmospheric electricity during a brief but productive period from 1859-1861. By
1859 Kelvin had recognised the need for "incessant recording" of atmospheric
electrical parameters, and responded by inventing both the water-dropper
instrument for measuring the atmospheric Potential Gradient (PG), and
photographic data logging. The water-dropper was widely adopted internationally
and is still in use today. Following theoretical considerations of electric
field distortion by local topography, Kelvin developed a portable electrometer,
using it to investigate PG on the Scottish island of Arran. During these
environmental measurements, Kelvin may have unwittingly detected atmospheric PG
changes during solar activity in August/September 1859 associated with the
"Carrington event". Kelvin's atmospheric electricity work presents an early
representative study in quantitative environmental physics, through the
application of mathematical principles to an environmental problem, the design
and construction of bespoke instrumentation for real world measurements and the
limitations of the original theoretical view revealed by experimental work.
