"Miller, or Graham, or both, were for years quite incredulous as to
Joule's results, because they all depended on fractions of a degree of
temperature--sometimes very small fractions. His boldness in making such
large conclusions from such very small observational effects is almost
as noteworthy and admirable as his skill in extorting accuracy from
them. I remember distinctly at the Royal Society, I think it was either
Graham or Miller, saying simply he did not believe Joule, because he had
nothing but hundredths of a degree to prove his case by."

The friendship formed between Joule and Thomson in 1847 grew rapidly.
A voluminous correspondence was kept up between them, and several
important researches were undertaken by the two friends in common. Their
first joint research was on the thermal effects experienced by air
rushing through small apertures The results of this investigation give
for the first time an experimental basis for the hypothesis assumed
without proof by Mayer as the foundation for an estimate of the
numerical relation between quantities of heat and mechanical work, and
they show that for permanent gases the hypothesis is very approximately
true. Subsequently, Joule and Thomson undertook more comprehensive
investigations on the thermal effects of fluids in motion, and on the
heat acquired by bodies moving rapidly through the air. They found the
heat generated by a body moving at one mile per second through the air
sufficient to account for its ignition. The phenomena of "shooting
stars" were explained by Mr. Joule in 1847 by the heat developed by
bodies rushing into our atmosphere.

It is impossible within the limits to which this sketch is necessarily
confined to speak in detail of the many researches undertaken by Mr.
Joule on various physical subjects. Even of the most interesting of
these a very brief notice must suffice for the present.