itution to the then recent work
of L. P. Cailletet and R. P. Pictet, and exhibited for the first time in
Great Britain the working of the Cailletet apparatus. Six years later,
in the same place, he described the researches of Z. F. Wroblewski and
K. S. Olszewski, and illustrated for the first time in public the
liquefaction of oxygen and air, by means of apparatus specially designed
for optical projection so that the actions taking place might be visible
to the audience. Soon afterwards he constructed a machine from which the
liquefied gas could be drawn off through a valve for use as a cooling
agent, and he showed its employment for this purpose in connexion with
some researches on meteorites; about the same time he also obtained
oxygen in the solid state. By 1891 he had designed and erected at the
Royal Institution an apparatus which yielded liquid oxygen by the pint,
and towards the end of that year he showed that both liquid oxygen and
liquid ozone are strongly attracted by a magnet. About 1892 the idea
occurred to him of using vacuum-jacketed vessels for the storage of
liquid gases, and so efficient did this device prove in preventing the
influx of external heat that it is found possible not only to preserve
the liquids for comparatively long periods, but also to keep them so
free from ebullition that examination of their optical properties
becomes possible. He next experimented with a high-pressure hydrogen jet
by which low temperatures were realized through the Thomson-Joule
effect, and the successful results thus obtained led him to build at the
Royal Institution the large refrigerating machine by which in 1898
hydrogen was for the first time collected in the liquid state, its
solidification following in 1899. Later he investigated the
gas-absorbing powers of charcoal when cooled to low temperatures, and
applied them to the production of high vacua and to gas analysis (see
LIQUID GASES). The Royal Society in 1894 bestowed the Rumford medal upon
him for his work in the production of low temperatures, and in 1899 he
became the first recipient of the Hodgkins gold medal of the Smithsonian
Institution, Washington, for his contributions to our knowledge of the
nature and properties of atmospheric air. In 1904 he was the first
British subject to receive the Lavoisier medal of the French Academy of
Sciences, and in 1906 he was the first to be awarded the Matteucci medal
of the Italian Society of Sciences. He was knighted