The Science Book

48

demonstration in 1654, when he put
two metal hemispheres together
with an airtight seal between them
and pumped the air out of them—
two teams of horses were unable
to pull the hemispheres apart.
Before the air was pumped out,
the air pressure inside the sealed
hemispheres was the same as the
air pressure outside. Without the air
inside, pressure from the outside
air held the hemispheres together.
Robert Boyle learned of von
Guericke’s experiments when they
were published in 1657. To do

experiments of his own, Boyle

commissioned Robert Hooke (p.54)

to design and build an air pump.

Hooke’s air pump consisted of a

glass “receiver” (container) whose

diameter was nearly 16 in (40 cm),

a cylinder with a piston below it,

and an arrangement of plugs

and valves between them.

Successive movements of the

piston drew more and more air out

of the receiver. Due to slow leaks

in the seals of the equipment, the

near-vacuum inside the receiver

could only be maintained for a

short time. Nevertheless, the

machine was a great improvement

on anything made previously, an

example of the importance of

technology to the furthering

of scientific investigation.

Experimental results

Boyle performed a number of

different experiments with the

air pump, which he described in

his 1660 book New Experiments

Physico-Mechanical. In the book,

ROBERT BOYLE

Otto von Guericke built the first air

pump. His experiments with the pump

provided evidence against Aristotle’s

idea that “Nature abhors a vacuum.”

he was intent on pointing out that

the results described are all from

experiments, since at the time even

such noted experimentalists as

Galileo often also reported the

results of “thought experiments.”

Many of Boyle’s experiments

were directly connected to air

pressure. The receiver could be

modified to hold a Torricelli

barometer, with the tube sticking

Men are so accustomed to

judge of things by their senses

that, because the air is

indivisible, they ascribe but

little to it, and think it but

one remove from nothing.

Robert Boyle

Robert Boyle Robert Boyle was born in Ireland,

the 14th child of the Earl of Cork.

He was tutored at home before

attending Eton College in England

and then touring Europe. His

father died in 1643, leaving him

enough money to indulge his

interest in science full time. Boyle

moved back to Ireland for a couple

of years, but lived in Oxford from

1654 to 1668 so that he could do

his work more easily, and then

moved to London.

Boyle was part of a group of

men studying scientific subjects

called the “Invisible College,”

who met in London and Oxford

to discuss their ideas. This

group became the Royal Society

in 1663, and Boyle was one

of the first council members.

In addition to his interests

in science, Boyle performed

experiments in alchemy and

wrote about theology and the

origin of different human races.

Key works

1660 New Experiments

Physico-Mechanical:

Touching the Spring of the

Air and their Effects

1661 The Sceptical Chymist