WILLIAM   THOMSON	221
conditions of their country prevented them from receiving
the understanding and support that they deserved for dis-
coveries fundamental to the development of a scientific
industrialism.
Joule had described some of his researches on the
mechanical equivalent of heat to the British Association
meetings in 1843 and 1845, without arousing any interest
or conviction. He spoke again at Oxford in 1847.
Thomson was a member of the audience and had previously
decided to rise and criticize Joule's discourse, but as he
listened he became convinced that though Joule was wrong
in some points,, on others he was communicating very
important truths; so he decided not to speak in the dis-
cussion but to talk to Joule afterwards. He introduced
himself and they swiftly became lifelong friends. It is
interesting to note that Thomson met two supreme experi-
menters in his youth, Faraday and Joule, and that he suc-
ceeded in establishing a close collaboration with one but
not with the other. Perhaps this was partly due to age, as
he was only six years younger than Joule, but thirty-three
years younger than Faraday. It may have been partly due
also to social outlook. Faraday, like Davy, carried into the
nineteenth century some of the modes of thought of the
educated classes of the eighteenth century. The educated
classes of the two centuries were different. Faraday and
Davy had been much affected by the culture of the govern-
ing class of the eighteenth century. This was the culture
of territorial magnates. Thomson and Joule grew up in
the Glasgow and Manchester districts respectively, chief
centres of industrial development. They had matured in
the culture of leaders of industrialism. Perhaps this helped
Thomson to know Joule more easily than Faraday.
The influence of industrialism on science is shown by
the interesting circumstance that Thomson wrote a short
paper on the theory of Stirling's hot-air engine, according
to Carnot's principles, two months before he met Joule.
At the end of this paper he had suggested that water at
32° F. may be converted into ice at 32° F. without the
expenditure of work.