plishments as
we proceed. It will be noted in due course that the work of some of them
was anticipatory of great achievements of a later century.

ROBERT BOYLE (1627-1691)

Some of Robert Boyle's views as to the possible structure of atmospheric
air will be considered a little farther on in this chapter, but for the
moment we will take up the consideration of some of his experiments
upon that as well as other gases. Boyle was always much interested
in alchemy, and carried on extensive experiments in attempting to
accomplish the transmutation of metals; but he did not confine himself
to these experiments, devoting himself to researches in all the fields
of natural philosophy. He was associated at Oxford with a company
of scientists, including Wallis and Wren, who held meetings and made
experiments together, these gatherings being the beginning, as mentioned
a moment ago, of what finally became the Royal Society. It was during
this residence at Oxford that many of his valuable researches upon air
were made, and during this time be invented his air-pump, now exhibited
in the Royal Society rooms at Burlington House.(1)

His experiments to prove the atmospheric pressure are most interesting
and conclusive. "Having three small, round glass bubbles, blown at the
flame of a lamp, about the size of hazel-nuts," he says, "each of them
with a short, slender stem, by means whereof they were so exactly poised
in water that a very small change of weight would make them either
emerge or sink; at a time when the atmosphere was of convenient weight,
I put them into a wide-mouthed glass of common water, and leaving them
in a quiet place, where they were frequently in my eye, I observed that
sometimes they would be at the top of the water, and remain there for
several days, or perhaps weeks, together, and sometimes fall to the
bottom, and after having continued there for some time rise again. And
sometimes they would rise or fall as the air was hot or cold."(2)

It was in the course of these experiments that the observations made by
Boyle led to the invention of his "statical barometer," the mercurial
barometer having been invented, as we have seen, by Torricelli, in 1643.
In describing this invention he says: "Making choice of a large, thin,
and light glass bubble, blown at the flame of a lamp, I counterpoised
it with a metallic weight, in a pair of scales that were suspended in
a frame, that would turn with the thirtieth part of a