spinning wheel, spinning work was readily available to wives. In the
1670s, a female weaver or spinner was paid 2-4d. per day. A domestic
servant, who was usually female, was paid 40-80s. a year. Men in the
trades objected to competition from lower-paid women. Aristocratic
ladies actively managed their family's household and estates. The only
work available to a high middle- class woman who was waiting to get
married was to be a governess in another household or a lady-in-waiting
to a gentlewoman. Children often worked; this was recommended so that
they were under the direct supervision of their parents rather than
getting into mischief in the village. The mother typically mingled
severity with gentleness, but the father did not dare to err on the side
of leniency. Discipline was by whipping. Children were treated as little
adults. The lack of a conception of childhood innocence even extended to
the practice of adults to tell bawdy jokes in their presence or play
with their children's genitals.
About 1660, the Royal Society of London for the Promotion of Natural
Knowledge was founded by Charles II, who became its patron. It was
formed from discussion groups of the new experimental philosophy. It
included the Baconians formerly at Oxford and Cambridge, who were
ejected at the Restoration, and a group of Gresham professors of
geometry and astronomy. The Royal Society met at Gresham College. Its
goal was to compare ideas in mathematics and science and identify
specific aims of science. It published scientific reports to make its
findings generally known. This was a great improvement over the private
correspondence among scientists, which was limited by the use of various
languages. Charles himself had his own laboratory and dabbled in
chemistry and anatomy. Similar societies were formed in many places in
the world. Theologicians warned that scientific research was dangerous.
But it's advances improved agriculture, manufactures, medicine, surgery,
navigation, naval architecture, gunnery, and engineering.
Issac Newton was a genius, who in his childhood designed and built
model windmills, water wheels, water clocks, sundials, and kites. He
came from a family which had risen from the yeomen ranks to the gentry.
For a few years after graduating from Cambridge University in 1665, he
secluded himself in the countryside to study. Here, using the work of
John Wallis, he formulated the binomial theorem that expands (A+B)
raised to the nth exponent power, where n is an integer. He also worked
with numbers that had exponents that were fractions, unending decimals,
or negative numbers. Certain patterns of numbers, such as the sum of
doubling each number in a series as in: 1+2+4+8+...never terminates; the
series is infinite. He then developed the notion of a number being the
limit of the summation of an infinite converging series of a pattern of
numbers, such as the limit of 1+(1/2)+(1/4)+(1/8)...= 2. By
considering the state of motion of a mass-point in an infinitely short
time under the influence of an external force, he developed rules for
finding areas under algebraic curves [integration], such as the
hyperbola, and finding tangents to algebraic curves [differentiation],
which he recognized as inverse processes. That is, differentiating the
integral of a function results in a return to that function.
Newton discovered that colors arose from the separation, rather than a
modification, of white light, that is natural sunlight. He did this
using a prism to dissect the white light into its spectrum of
constituent colors and then using a prism and lens to recombine the
colors to reconstitute white light. The spectrum was the same as that of
a rainbow. He determined the angle of refraction of each color by
beaming white light through a prism, and then through a hole in a board
which isolated one color, to another prism. When he discovered that all
colors reflect from a mirror at the same angle, he invented and built
the reflecting telescope, which used a parabolic concave mirror and a
flat mirror instead of a convex lens, thereby eliminating the
distortions and rainbow coloring around the edges that resulted from the
refraction of different colors at different angles. He deemed a ray of
light to consist of a rapidly moving stream of atomic particles, rather
than Robert Hooke's pulses or Christian Huygens' waves, because shadows
showed a sharp boundary between the light and the absence of light. He
reasoned that if light was made up of pulses or waves, it could spread
around obstacles or corners as sound seemed to do. He approximated the
speed of sound by timing echoes in corridors of various lengths.
Newton was methodical and combined the inductive and deductive methods
of inquiry, first making observations, and then generalizing them into a
theory, and finally deducing consequences from the theory which could be
tested by observation. He carried mathematization of data from
experiments as far as possible.
Newton theorized that the same gravity force that pulled an apple down
from a tree extended out to the moon to hold it in its orbit around the
earth. He saw a connection between these movements by imagining a cannon
on a mountain shooting a series of cannonballs parallel to the earth's
surface. The first shot has only a tiny charge of explosive, and the
cannonball barely makes it out of the muzzle before falling to the
ground. The second shot is propelled by a larger charge, and follows a
parabolic arc as it falls. The next shots, fired with increasingly more
propellant, eventually disappear over the horizon as they fall. Lastly,
with enough gunpowder, a speeding cannonball would completely circle the
earth without hitting it. By extrapolating from these ever faster
projectiles, he opined that the moon was held in its orbit by the same
earth force that operated on the projectiles. He correlated the moon's
orbit with the measured acceleration of gravity on the surface of the
earth. He put various substances with different masses and weights into
the shell of a pendulum and observed that the pendulum had the same
period [time for one oscillation] and fell at the same rate as
free-falling objects. Then he formulated the idea that the ultimate
agent of nature was a force acting between bodies rather than a moving
body itself. Gravity did not act in proportion to the surfaces of
bodies, but in proportion to quantity of matter. Gravity penetrated to
the very center of all bodies without diminution by the body. Gravity's
force extended to immense distances and decreased in exact proportion to
the square of the distance.
Newton opined that an object moves because of external forces on it
rather than by forces internal to the object. These are his three laws
of motion. 1) He connected the concepts of force and acceleration with a
new concept, that of mass. Mass is a quantity intrinsic to an object
that determines how it responds to forces, such as the force of gravity.
The greater the mass of a body, the stronger the force of gravity on it,
and the more difficult it is to get it moving. He found that the
acceleration of a body by a force is inversely proportional to its mass,
and formulated the equation that force equals mass multiplied by
acceleration. So if a force acts on a planet, it produces a change in
velocity that is proportional to the force and in the same direction as
the force.2) His law of inertia is that any body, persists in its state
of rest or of uniform motion in a straight line, unless affected by an
outside force. 3) His next law is that when a body A exerts a force on a
body B, then B also exerts a force on A which is equal in amount but
opposite in direction. This means that forces that operate between
different parts of a planet produce no net force upon the whole planet,
so that the mass of a planet can be treated as if it is concentrated at
a point.
His law of gravitation explains how the whole universe is held
together. This law holds that every object in the universe attracts
every other object with a single gravitational force that is directly
proportional to the product of their masses and inversely proportional
to the square of the distance between their centers. Newton had at first
accepted the Cartesian system of celestial vortices of aether that
swirled the planets and comets around their orbits. He determined that
Kepler's law that areas were swept out in equal times implied that
gravity acts in the direction of a line between the planet and the sun.
The gross features of the universe and Kepler's observations led to his
recognition that the attraction between two bodies decreases inversely
in proportion to the square of the distance between them. Only one kind
of force would satisfy Kepler's requirement that the sun was a focus of
an ellipse and still be consistent with Kepler's law that the square of
a planet's period was proportional to the cube of its mean distance from
the sun; that was the inverse square law. Then he came to accept Robert
Hooke's hypothesis that planets are kept in their orbits by the
combination of an attractive power of the sun and of motion in a
straight line that was tangential to their orbits. From astronomical
data, he calculated this centripetal acceleration of each planet towards
the sun to be proportional to the inverse square of its distance from
the sun. He also calculated the "centrifugal" accelerations in a
straight line. His experiments showed that the centripetal force in a
circular orbit was equal to the mass of the body multiplied by the
square of its velocity, all divided by the radius of the circular path.
He used calculus and differential equations to determine centripetal
forces of elliptical orbits, where the distance from the sun, the
velocity, and the acceleration were variables.
Newton showed that his single gravitational force could account for the
way free-falling objects descend to the ground, the parabolic trajectory
of projectiles, the path of the moon in its orbit around the earth, the
course of the tides every twelve hours, the lower densities of the
earth's atmosphere at greater heights, the paths of Jupiter's moons, the
paths of comets, and the elliptical paths of the planets in their orbits
around the sun. This determination discredited the previous belief that
invisible angels moved the planets. Newton proved from his law of
gravitation and his three laws of motion the truth of Kepler's laws of
elliptical planetary motion. Newton demonstrated from data collected
from the comet of 1680 that comets moved according to his law of
gravitation. He showed that the path of a body traveling within the
gravitational force of the sun is a circle, an ellipse, a parabola, or a
hyperbola. He used the concept of a common center of gravity as a
reference point for other motions. The fact that the center of gravity
of the solar system was within the body of the sun verified that the sun
was indeed at the center of the solar system.
Newton deduced that the tides were created by the rotation of the earth
with bulges of water on the earth's surfaces that were closest and
farthest from the moon. The moon "pulled" the water nearest to it with a
greater force than average. It "pulled" the water farthest from it with
a force weaker than average. These two moving bulges created two tides a
day.
Newton's "Principia Mathematica Philosophiae Naturalis", was published
in 1687. The established church denounced it as being against the
scripture of the Bible. Newton did not agree with the established church
on many points, such as the trinity, and was considered a heretic. He
had his own interpretations of the Bible and doubted the divinity of
Jesus. But it was accepted for dissenters like Newton to qualify for
full civil rights by maintaining an outward conformity and taking the
sacrament in the established church once a year. Newton was given a
royal dispensation from taking holy orders as prescribed by the rules
for tenure of fellows of his college at Cambridge University. He did
believe in a God who created the universe and who had a ubiquitous
presence in all space. When Catholic King James II tried to have a
Catholic monk admitted to the degree of a Master of Arts at Cambridge
University without taking the oath of adherence to the established
Protestant church, so that he could participate in the business of the
university, Newton was active in the opposition that defeated this
attempt. As a result, he was elected to Parliament by Cambridge.
When Olaus Roemer, a Danish astronomer, was applying Newton's laws to
the paths of the moons of Jupiter to make a table of eclipses of
Jupiter's moons for use in determining one's longitude, he noticed that
the eclipses were five hundred seconds ahead of average time at that
time of year when the earth and Jupiter were on the same side of the
sun, and five hundred seconds behind average time six months later, when
Jupiter was on the other side of the sun. He reasoned that this
difference was due to the light from Jupiter's moons taking more time to
reach the earth when Jupiter was farther from the earth, i.e. on the
other side of the sun. He concluded that light does not travel
instantaneously, but at a certain speed. From the fact that it took 1000
seconds for light to travel the diameter of the earth's orbit, he
calculated its speed in 1676.
In 1668, Christian Huygens formulated the law of conservation of
momentum [mass multiplied by velocity], which held that when objects
collide, they may each change direction, but the sum of all their
momenta will remain the same. Huygens also recognized the conservation
of what was later called "kinetic energy", which is associated with
movement. He developed laws of centrifugal force for uniform motion in a
circle. He derived the formula for computing the oscillations of a
simple pendulum. In 1690, he posited the theory that light consists of a
series of waves. It states that all points of a wave front of light in a
vacuum may be regarded as new sources of wavelets that expand in every
at a rate depending on their velocities. He thought this a better
explanation of bending and interference of light than Newton's particle
theory.
In 1661, Robert Boyle, called the father of modern chemistry, defined
an element as a substance that cannot be further decomposed. He
distinguished an element from both a mixture, which is easily separable,
and a compound, which is not easily separable. He used an air pump he
developed and a glass jar to create a confined vacuum space for
experiments to find the properties of heat, light, and sound. He noted
that burning objects such as candles and coal, when placed in the
receiver of his air pump, went out after a time although air was still
present. He opined that animals were dependent upon a fresh supply of
air to live. He studied the relationship between the volume, density,
and pressure of air and gases. He proved by experiment that the volume
of a gas at a constant temperature varies in inverse proportion to the
pressure applied to the gas. Since gas is compressible, he opined that
gases must be composed of discrete particles separated by void, and also
that basic physical properties were due to motions of particles, or
atoms, which was an ancient Greek conjecture. This cast doubt on the
long-held belief that everything was composed from four basic elements:
air, water, fire, and earth. Boyle's laboratory at Oxford was denounced
by the Oxford clergy as destroying religion. In 1679, the steam pressure
cooker was invented by Denis Papin from France. He invented the
atmospheric engine in 1690.
Robert Hooke helped Boyle build his air pump. Hooke was thirteen when
his father, a minister, died. Hooke was a genius with innate mechanical
skill and was an able mathematician. He applied a spiral spring to
regulate the balance of watches. A lord financed him as a Gresham
lecturer of geometry for 50 pounds a year. In 1666, he used a pendulum
to measure the force of gravity and showed that the center of gravity of
the earth and moon is a point describing an ellipse around the sun. In
1667, he explained the twinkling of the stars by irregular atmospheric
refractions. He formulated the theory that light is composed of pulses.
Hooke's Law states that the amount an elastic body such as a spring
stretches out of shape is in direct proportion to the force acting on
it: its tension. He invented the odometer, a wheel to measure distances.
He constructed an arithmetical machine. He invented the universal joint,
which can move in many angles. His book of drawings of microscopic
animals is a classic. He proposed that fossils can be used as a source
of information about the earth's history. Hooke became rich from his
inventions, but this was not known until his death, when thousands of
pounds were found in his iron chest.
In 1668, Wallis postulated the correct theory of impacts of inelastic
bodies, based on the principle of conservation of momentum. In 1685, he
introduced the first graphical representation of complex numbers.
Royal astronomer and genius Edmond Halley, the son of a soap maker,
studied tides, magnetism, and the paths of comets and stars. He went on
voyages to study the heavens from different positions, thereby laying
the foundations of physical geography. He showed that the stars change
in position in relation to each other. With Newton's help, he calculated
the orbit of a comet he saw in 1682 to be elliptical rather than
parabolic and then proved it was the same comet that had appeared in
1531 and 1607, indicating it's regularity; it was then named "Halley's
comet". However, the Church of England still embraced the idea that
comets and eclipses were evidence of God's wrath. Greenwich Observatory
was built in 1675. Halley used a barometer to measure the density of the
atmosphere and related its readings to elevations into the atmosphere
and to weather. He determined that the cause of the tropical trade winds
was the sun warming the tropical air at the equator, causing it to rise
and move north as it was replaced by cooler air from the north. This
body of air was deflected by the rotation of the earth. He illustrated
the tropical winds with the first meteorological map. He made a descent
in a diving bell, which was used to try to reach wrecked treasure ships.
He studied fossils and perceived them as remnants of living beings that
had died long ago, and imagined a succession of living things. Halley
surveyed the tides and coasts of the British Channel for the king in
1701.
In 1675, apothecary Nicolas Lemery divided substances into mineral,
vegetable, and animal. He wrote a dictionary of pharmaceuticals.
John Ray and Francis Willoughby were friends who traveled together to
study plants and animals respectively. John Ray started the science of
zoology with his edition of Francis Willoughby's "Ornithology" on birds
and his own "History of Fishes". He also attempted the first scientific
classification of animals in his "Synopsis of Quadrupeds". Ray compared
anatomies and experimented on movements of plants and the ascent of sap.
He knew that fossils were remnants of old animals. Ray first suggested
the concept of species in classification of animals and plants. He
opined that the goodness and wisdom of God was shown not only by the
usefulness of animals to man's uses as taught by the church, but also by
the adaptation of animals to their own lives and surroundings. The vast
array and dispersal of animals found by world explorers all over the
world cast doubt on the biblical story of Noah putting two of every kind
of animal on an ark. The science of botany began with Ray's "History of
Plants" and the researches of Robert Morrison, who was Charles'
physician and keeper of his gardens.
Nicholaus Steno, a Danish physician, diagrammed six levels of
stratification on the earth's surface and demonstrated in 1669 that
layers of strata of rock are always deposited with the oldest layers on
the bottom and the youngest layers on the top. This began the science of
geology. He argued that shifts in the earth's strata caused the
formation of mountains. He identified fossils as ancient creatures. The
idea that fossils were remnants of dead animals existing before man
conflicted with the religious idea that Adam's fall began sin and caused
death. The idea from fossils that existing species of animals were
modifications of predecessor animals conflicted with the religious
belief that Noah's ark had preserved all the varieties of animals. John
Aubrey described Stonehenge, thus founding prehistoric archaeology. He
thought it to be a Druid temple.
The telescope and compound microscope, which has an objective lens and
an eyepiece lens for producing a wide range of magnifications, were
further developed. The cellular basis of life was discovered and
described by Robert Hooke. Nehemia Grew, the son of a grammar school
master who became a physician, observed and drew plant anatomy,
including leaves, flowers, fruits, seeds, ovules, pollen grains, and
stamens. He was the first to observe the existence of plant sexuality.
Italian Marcello Malpighi, a physician, used the new compound microscope
to study human skin, spleen, kidneys, and liver and also compared the
livers of several types of animals. He discovered capillaries linking
the arterial and venous circulation in the lungs. Dutchman Anton van
Leeuwenhock, a cloth manufacturer who made microscopes to inspect the
quality of cloth, turned them to use in understanding the life cycles of
mites, lice, and fleas. He correctly described human blood cells. When
he found what he described as tiny animals (bacteria, protozoa, and
rotifers), he sent clear descriptions of them to the Royal Society in
London as proof against the theory of spontaneous generation, which held
that lower forms of life could arise from nonliving matter. This started
the science of bacteriology. With the discovery of the egg in the female
reproductive system, the status of women was lifted.
Physician Thomas Willis, son of a farmer, dissected brains of men and
animals to study the anatomical relations of nerves and arteries. Excess
urine had been associated with a wasting disease. Willis identified
diabetes mellitus with excess of urine that was sweet. Physician Thomas
Sydenham, son of a gentleman, observed epidemic diseases of London over
successive years, thus founding epidemiology. He also furthered clinical
medicine by emphasizing detailed observations of patients and
maintaining accurate records. He wrote a treatise on gout and identified
scarlet fever. He introduced a cooling method of treating smallpox. But
he still relied on the big three treatments: bloodletting, purging, and
sweating. Bloodletting was to draw off bad blood so that it could be
replaced by a better fluid. Another treatment used was cupping, whereby
a vacuum was created by heated glass cups to draw blood to the surface
of the skin. John Locke performed one of the first successful operations
draining a kind of abscess of a man's liver. It was common for people
who felt ill to take a laxative and rest at home.
In 1690, physicians opened the first dispensaries, which gave treatment
and medicine together, to take business away from their rivals: the
apothecaries. London's apothecaries were released in 1694 from jury
service and service as constable, scavenger, or other parish or ward
office because it was necessary that they be available to attend the
sick at all times. Peruvian bark which had quinine as its alkaloid had
been introduced as a proven cure for the ague, a fever with chills
usually due to malaria, in 1653. The English ceased to believe in holy
wells, but went to spas such as Bath for treatment of disease.
There was more bathing because private homes in towns now had indoor
baths. The public baths came into disuse.
For childbirth, only rich women were attended by physicians. Most
physicians used talismen such as the eagle stone at deliveries.
Caesarian section almost always led to the death of the mother. Midwives
were licensed by the church and could baptize babies. Jane Sharp wrote
"The Midwives Book" with anatomical illustrations.