University of Virginia Library

TECHNOLOGY

Civilization, even in a most elementary form, implies
a degree of command over nature. Indeed, in its early
stages, a civilized community, so far as it can be stud-
ied, may be said to be coextensive with its technics.
It seems likely however that once a society reaches
a certain stage in the development of technics and of
social organization it faces, in effect, a wide choice
of options. Thus it may seek wealth and power by
enslaving its neighbors or by compelling them to pay
tribute; it may evolve a bureaucratic form of govern-
ment, or become a theocracy or a military tyranny.
In any of these cases it is unlikely that there will be
much further progress in technics; for they provide
alternative and rival solutions to the problems which
would otherwise be solved by technics, or else they

induce a static society in which inventive impulses are
stifled.

The civilization of China, ancient, extensive, and
resilient, gave the world a number of great inventions
of which the most prominent were probably paper and
gunpowder. Yet, in spite of the evident genius of the
individual Chinese inventor, the total achievement was
disappointing. Chinese technics could not overcome
the obstacles which, one infers, a static society put in
the way. Inventiveness in China seems to have been
diverted from its basic purpose of satisfying wants and
needs; instead a great deal of effort was apparently
put into what may be called “frivolous invention”; that
is, into creating amusing toys such as kites, puzzles,
games, automata, and firecrackers. It is only fair to add,
however, that “frivolous invention” was well known
in medieval and Renaissance Europe and is not
uncommon in the modern world! In the case of China
we may tentatively assume that the diversion and
ultimate frustration of the inventive impulse was due
to the values inculcated by the powerful bureaucracy,
the low esteem in which utilitarian motives were held,
and the real lack of incentives to economic activity.

The experiences of classical antiquity tend to confirm
that the progress of technics can be arrested at any
stage by unfavorable social influence. In particular it
has frequently, and plausibly, been suggested that the
institution of slavery accounts for the ultimate failure
of Greek and Roman science and technics. On the other
hand it must be admitted that the ancient civilizations
of the Middle East had many technical achievements
to their credit, especially in such fields as metallurgy
and civil engineering. The Greeks, who were seafarers
and traders, were little concerned with technics and
made few significant inventions. Yet one may hazard
the guess that, after the foundation of Alexandria, when
Greek genius fused with the more pedestrian but com-
plementary abilities of the Egyptians, there was at last
the real possibility of a progressive science and tech-
nology. Egyptians seem to have been in some respects
curiously free from that deep-seated fear of nature
which troubled all other men, including Greeks and
Romans. The Egyptians practiced human dissection;
they were also skilled metallurgists. By repute experi-
mental chemistry, in the form of alchemy, began in
Egypt. Egyptians were of necessity expert irrigation
engineers and hydrologists and they introduced such
useful inventions as the water clock, or clepsydra, and
the Archimedean screw. Was it perhaps symbolic that
the only one of the Seven Wonders of the ancient world
which served a useful purpose and was not an instance
of conspicuous consumption was the Pharos at Alex-
andria?

The science of Alexandrians like Eratosthenes, Hero,
and Ptolemy had the professional touch which was
lacking in Hellenic speculative thought. But unfor-
tunately Alexandria, with its famous Museum and Li-
brary, had no rival, no stimulating partner, anywhere
in the ancient world. Experience suggests that if sci-
ence and technics are to flourish several competing
centers of excellence are required: if there is only one
the opportunities for profitable debates are so restricted
that intellectual stagnation is sooner or later inevitable.
As for the rest of the then civilized world, the major
cities exemplified not so much technical abilities as the
administrative gifts of the Roman rulers.

With the slow rise of Christian Europe from the
ruins of the Roman Empire, a new form of society
emerged that was to prove favorable for the renewed
advance of technics. The reasons for this are probably
many and certainly complex. Nevertheless specific and
readily identifiable features of this society must have
been important. For one thing the universal acceptance
of a dogmatic monotheistic religion was associated with
the establishment of a common educational or cultural
system of which a characteristic feature was the medi-
eval university. Again, the nature of Christian teaching
meant, or at least could mean, the dismissal from nature
of all arbitrary wills—the whole pantheon of gods,
goddesses, and minor spirits—and the substitution of
one rational, omnipotent, and benevolent God as Ar-
chitect of the Universe and ruler of all things. The
consequence of such a belief for the advance of tech-
nics as well as of science need hardly be emphasized.
But perhaps most important of all, the Europeans
revealed an admirable willingness to learn from out-
siders.

At the dawn of the Middle Ages, which we assume
began with the reign of Charlemagne, the Europeans
were undoubtedly inferior to the contemporary Arabs
and Chinese in both technics and the arts of living.
They had, however, sufficient humility to admit this,
tacitly at least, and in the following centuries they
freely copied the inventions and the arts of the civili-
zations of Asia and Africa. In fact, a readiness to imitate
appears to be essential for the spread of invention and
for the furtherance of technics in general: this seems
to be as much a characteristic of progressive industrial
enterprises in the modern world as of progressive na-
tions and civilizations in the past. It is only by imitat-
ing, by copying and adapting, that a class of technicians
can be built up; and it is mainly from such a class that
one may expect original inventors to emerge in due
course. It follows that historians who extol the Arab
and Chinese civilizations at the expense of medieval
Europe miss an essential point. After all, the first ques-
tion to ask about any invention is not who made it,
but how widespread was its use.

If we assume that the Middle Ages ended with the
fifteenth century then a simple count of inventions
made or adopted by Europeans during the period
confirms that it was, as regards technics, more creative
than any previous epoch in recorded history. Among
the more important medieval inventions were the
stirrup, paper, gunpowder, firearms, the weight-driven
clock, the mariner's compass, the spinning wheel, the
Saxon plough, the windmill, the crank, the horse collar,
the steering rudder, the printing press, and the three-
masted ship. Most of the earlier inventions were copied
from the Arabs and the Chinese; most of the later ones
were made by Europeans themselves. Many were most
likely made simultaneoulsy but independently by
different men in Europe and elsewhere; scholars have
long recognized that simultaneous invention is a very
common occurrence.

The weight-driven clock, perhaps the most re-
markable of all medieval inventions, appeared, it is
believed, towards the end of the thirteenth century
having in all probability evolved from a long line of
astronomical models. The mechanical clock does not
measure the duration between two events, as an hour
glass or a calibrated candle does; as its circular dial
and moving hand indicate, it is really a device for
indicating the position of the sun with respect to a
meridian of the (supposedly) fixed earth.

The apparent diurnal motion of the sun is for all
practical purposes uniform. But it is impossible to
obtain continuous uniform motion from any motive
agent without some form of self-controlling or feed-
back mechanism.

In the medieval weight-driven clock this problem
is solved by combining a basic principle with a
brilliantly ingenious kinematic invention. The uniform
and constant force of gravity, acting on a suspended
weight, is transformed by means of an escapement
wheel into an alternating horizontal force which is then
applied to an inertial system consisting of two equal
masses at the opposite ends of a horizontal, centrally
pivotted rod. The inertial system, driven by the cyclic
force, oscillates to and fro with a uniform beat whose
period, or duration, is determined by the geometry of
the machine and the magnitudes of the weights and
masses. The invention of the escapement wheel could,
in principle at any rate, have been made at any time;
but the basic physics of the weight-driven clock was
not formulated until the seventeenth century: as the
foregoing words “force,” “inertial,” and “masses”
imply. One may, therefore, properly designate this
invention as precocious, for it was based on principles
which could not be scientifically explained at the time.

Crude as the first weight-driven clocks were, the
process of “evolutionary” improvement assured rapidly
rising standards of precision, reliability, and lightness:
a process punctuated and expedited by such “revolu-
tionary” improvements as the inventions of the fusee,
the stackfreed, the spring or “clockwork” drive, the
pendulum clock, and the anchor escapement. Before
very long a class of skilled clockmakers, the first of
the precision engineers, was established. This had ob-
vious economic and technical importance. On another
plane, however, the mechanization of time measure-
ment had very far-reaching consequences. Throughout
antiquity and up to the middle of the fourteenth cen-
tury it had been customary to divide the period be-
tween sunrise and sunset into an equal number of hours
with the consequence that the length of the hour varied
with the length of the day; with, that is, the time of
the year. This was a reasonable procedure in days when
there were no powerful sources of artificial light so
that most communal activities ceased with nightfall.
Accordingly it was the practice to calibrate sundials
with hour marks to suit the time of year. But with
the advent of the mechanical clock the practice of
astronomers, who had long taken the length of the hour
to be uniform by day and by night, now became the
common practice of all men. The public clock, on
church or castle, proclaimed the time to all men. With
the improvement in clocks went the further subdivision
of the uniform hour into uniform minutes and seconds.
This meant that all men could now regard time as an
infinitely extended dimension against which all events
and affairs were ordered. It was not so much the inter-
val between specific events as an eternal process
underlying them. Ever since the Middle Ages the
steady, uniform tick of the clock has marked the pas-
sage of time in this cosmic sense. It is hardly surprising
therefore that the mechanical clock inspired the famil-
iar and persuasive seventeenth-century image of a
“clockwork” universe and no doubt it contributed to
Newton's formulation of absolute, true, and mathe-
matical time which, he asserted, flows equably without
relation to anything external.

No doubt, the geometrization of time also owed
something to the revival of interest in Euclid in the
Middle Ages and to mathematically inclined philos-
ophies such as the various forms of Platonism. So, too,
did the geometrization of space which helped artists
to invent new techniques of painting pictures as “true
to nature” and not as symbolic representations. At a
more humdrum level the development of cartography
marked the same sort of change when symbolic dia-
grams, such as the T-O maps, gave place to realistic
representations of land forms.

Accompanying and reinforcing the emergent tech-
nics of the Middle Ages was a new attitude to nature
which was, in part, a product of Christian teaching.

But it had other roots too, for an important component
of the new attitude was the rise of what have been
called the heretical sciences—alchemy, astrology, and
magic. These represented a bold attempt to appro-
priate the secret and innermost processes of nature;
in Robert Lenoble's expressive phrase, to break the
“tabu on the natural.” However we apportion the
credit for the new attitude, there can be no doubt that
men became more courageous and enterprising in the
face of nature. One aspect of this was the relaxation
in the medical schools of the medieval universities of
the ancient prohibition of human dissection.

At the same time the mining industries of Europe
were being developed, differing from the practice of
the ancient world in that the miners were now free
men and not condemned slaves. Mining was, from the
early days, big business. It needed not only large-scale
social and financial organization but also the services
of a wide range of technics. It posed problems in civil
engineering, in ventilating and pumping and hence in
the generation of power, in underground and surface
transport, and in the treatment of metals. Accordingly
mining expedited the growth of applied sciences such
as metallurgy and “pure” sciences such as chemistry
and geology. Indeed, the acknowledged excellence of
German chemistry was said to have been due to the
extensive mining industries of that country. In short,
mining has been one of the seedbeds of Western science
and technology.

The last aspect of medieval and Renaissance technics
that we shall mention was the proliferation of attempts
to devise a perpetual motion machine. This utilitarian
aspiration was based on the consideration that perpet-
ual motion was not an absurdity: the motion of the
heavens, the tides, streams and rivers, and the winds
are all apparently “perpetual.” And it was not until
after the “Scientific Revolution” of the seventeenth
century and the demonstration that the atmosphere
acts as a heat engine powered by solar energy that
the rational basis for the attempt to make such ma-
chines was finally destroyed.

Medieval and Renaissance perpetual motion ma-
chines, indeed machines in general, were characterized
by an exuberant delight in elaboration: gear trains were
added merely for the sake of complexity as well as
in the hope of hitting on a more subtle science of
mechanics that would transcend mere earthbound me-
chanics. The latter endeavor failed, but not before men
had taught themselves a great deal about the principles
of machines. The period was intensely machine-
conscious, as the famous notebooks of Leonardo testify.

When we consider medieval technics in retrospect
we can see that they affected intellectual life in several
different ways. In the first place certain inventions may
of themselves cause fundamental changes in thought.
Thus the widespread application of the mechanical or
weight-driven clock necessarily changed, or helped to
change, men's ideas about time, compelling everyone
to accept the notion of the uniform hour, minute, and
second and furthermore to consider time as a process
which transcends all particular events. In addition the
machine itself suggested a model for the universe which
many found particularly satisfying. Again, technics
provides men with new and improved tools which, in
enabling him to extend his mastery over nature, also
serve to extend his knowledge. The invention of the
mariner's compass coupled with improvements in ship
building and design enabled Portuguese and Spanish
navigators to extend knowledge of the world from the
margins of Europe to the vast globe itself—now
actually confirmed to be a globe—over which the
observed laws of nature were found everywhere to be
uniform and constant. Finally, we recognize that the
development of technics may change the course of
thought by ameliorating the conditions of life, by
providing cumulative evidence that men may hope
increasingly to determine their own destinies—that is,
by giving sanction to the idea of progress—and by
assisting in the spread of secular learning. The last is
exemplified by the great medieval invention of the
printing press.

The achievements of the period which ended in 1500
A.D. provided a good deal of the knowledge, in terms
of hard-won experience, and much of the morale and
inspiration for that remarkable movement which swept
Western Europe in the seventeenth century and which
is known as the “Scientific Revolution.” The distinctive
creed of the new movement was the “mechanical
philosophy,” an expression which neatly summed up
its adherents' indebtedness to medieval and Renais-
sance mechanical inventors: those whom Leonardo
Olschki has called the “artist-engineers” who flourished
notably in northern Italy. Only a mature civilization,
urban and technical rather than rural, could have given
rise to the mechanical philosophy. In fact the greater
part of medieval technics had been forged in the cities
of northern Italy and of southern Germany. The Italian
cities tended to excel in the mechanical arts, architec-
ture, and civil engineering; the German cities in the
metallurgical and chemical arts (Gutenberg, the
inventor of the printing press was, significantly, a
goldsmith by trade).

Peripheral Europe—i.e., Britain, Scandinavia, the
Iberian Peninsula, North Germany, and Poland had,
in comparison, done very little. Yet with the scientific
revolution the center of gravity of technics—and of
science—began to move towards the north and the
west, just as, five hundred years earlier, it had moved

in the same direction when the Italians and South
Germans took up the technics of Africa and Asia.

The century of revolution and of change was notable
for many men of genius. We shall consider, briefly, two
such men whose works proved to be complementary.
One, Galileo, was a genius who built on the achieve-
ments of his predecessors. The other, Francis Bacon,
contemplating the triumphs of the past and considering
the negligible contributions that his fellow countrymen
had made, drew up a program or plan for the conscious
advancement of technics which, in detail, in insight,
and in eloquence of exposition, had not been rivalled
up to his day; nor, one may guess, has it been rivalled
since.

Galileo's method of science need not be discussed
in detail. It was based on a Platonic faith in a mathe-
matical order in nature, on the practice of abstraction
and intuition of the form of individual mathematical
laws of nature, and also on the use of experimental
test, under conditions as close to the ideal as possible.
The rise of such a philosophy in a machine-conscious
community is hardly surprising. But if it owed some-
thing to practical mechanics—as the opening words
of Galileo's Two New Sciences indicate—it was in
return able to make a fundamental contribution to the
advancement of practical mechanics. For, following
Galileo's work, an ancient but fundamental fallacy
founded in common sense and experience was removed
from mechanics. Experience shows that it always re-
quires more effort to work a machine than merely to
hold it in equilibrium. This had been generalized into
a plausible law; that the force required for motion is
always greater than the force required for equilibrium.
But the application of Galileo's principles of abstrac-
tion and idealization shows that this is not so: the
inequality arises not from some basic principle but
from the fact that all machines are imperfect: they
distort under load and they suffer from friction. A
friction-free and otherwise perfect machine would
ultimately be as easy to move as to hold in equilibrium.

This insight opened up a new vista for technics. A
numerical measure of the efficiency of machines now
became possible. The efficiency of a machine need not
be expressed in normative terms—this machine is
“better” than that one—but as a simple fraction. In
the case of a machine which is perfect in both design
and construction the fraction, which is the ratio of the
output of work to the input of power—or “effect” to
“effort”—is necessarily equal to unity. In any practi-
cable and therefore imperfect machine the fraction
must be less than one. But Galileo's work also leads
us to express the effort of any motive agent in terms
of a measurable unit of power since, if the agent is
applied to the simple and perfect machines (levers,
pulleys, gears, etc.), its effect, or the work done, must
always be numerically the same, for nothing is lost in
the working of a perfect machine.

Entailed therefore by the axioms of the seventeenth-
century science of mechanics were two basic and re-
lated concepts: that of the quantifiable efficiency of
machines and that of power. The quest for perpetual
motion was abandoned, for the logical implication of
the concept of efficiency is that restoration, or recov-
ery, of the initial situation is the utmost that can be
expected even of an ideal engine. In 1704 Antoine
Parent initiated a fruitful debate when he computed,
using the newly invented calculus, the maximum
efficiency of an “undershot” waterwheel of perfect
construction but inherently incapable, he believed
wrongly, of perfect operation. (The fact that the wheel
rotates diminishes the impact of the water on its blades,
while the water leaving the machine—the tailrace—
must have some residual velocity. These, apparently
unavoidable, defects must reduce the efficiency of the
machine. Eighteenth-century engineers were to dem-
onstrate how they could be eliminated.)

Francis Bacon's ideas were interesting mainly from
the social and political points of view. He commended
technical innovation in preference to military conquest
as the humane way of augmenting national wealth; he
identified the obstacles to the progress of science and
he pointed out that the supremacy of Europe was due
not so much to military or civic superiority, as to the
possession of certain key inventions such as firearms,
the printing press, and the mariner's compass.

Inventions, according to Bacon, fall into two more
or less distinct categories; those which can be made
only if the appropriate knowledge is available—we call
these science-based inventions—and those which are
substantially independent of scientific knowledge and
which could, therefore, have been made at any time
in the history of civilization; we may call the latter
“empirical” inventions. The obvious importance of the
former provides, in Bacon's view, strong additional
grounds for encouraging the progress of science, of the
acquisition of knowledge.

Bacon wrote before the “mechanical philosophy”
(e.g., of Boyle and Newton) appeared in England. He
was no mechanic and his advice, that if one wants to
command nature one must first learn to obey her,
suggests an attitude favorable for biological sciences
and technics. Generally, however, since his day the
mechanistic approach, exemplified by mechanical
engineering, physics, and chemistry, has triumphed.
Bacon serves to remind us that an alternative form of
technics might, conceivably, have developed since the
seventeenth century. But this is merely conjectural.
What is undeniable is that if we combine Bacon's broad

vision with the practical aspects of the new science
of mechanics we see how the practice of technics was
becoming self-conscious and at the same time increas-
ingly science-based. In short, “technology”—the word
was a neologism in the seventeenth century—was be-
ginning to replace the more elementary “technics.”

Up to the seventeenth century the English had been
mere imitators of German, French, Italian, and Dutch
inventions; they had been, indeed almost notoriously,
incapable of making inventions of their own. Never-
theless a considerable body of native craftsmen had
been built up and they began to show their quality
when, in 1712, Thomas Newcomen invented the first
successful “fire” engine. This was, in Bacon's sense, a
science-based invention for its operation depended on
harnessing the pressure of the atmosphere; a phenome-
non which had been discovered by seventeenth-century
scientists. Huygens and Papin, among others, had
envisaged such a machine. Newcomen's achievement
lay in devising it in thoroughly practicable form—
steam in a cylinder, fitted with a piston, is condensed,
leaving a void, so that the external atmospheric pres-
sure can act on the piston—and in making the engine
automatic or self-acting. His was not only a major
invention in its own right but one of the greatest
achievements in the history of technology, comparable
with the weight-driven clock and the printing press.

The main use for Newcomen's engine was as a mine
pumping engine and as such its progress in the first
half of the eighteenth century was slow but assured.
But in the second half it was associated with two
remarkable events. The first was when the engineer
John Smeaton (1724-92) applied to the design and
operation of the engine a new technique which can
be described as systematic evolutionary improvement.
One component of the engine is systematically varied,
all the rest being kept constant. The change in per-
formance of the engine is then noted with each varia-
tion of the component. The variation which gives the
best result is selected and the procedure is repeated
for each component in turn. In this way Smeaton could
obtain the best design and the conditions for the best
performance of a machine of given size.

This systematic technique had obvious affinities with
the experimental procedures of the time and, quite
possibly, with those of Newton in particular. Equally,
it was obviously a corollary of the Galilean theory of
machines, for the possibility of optimizing the per-
formance of an engine in such a way depends on prior
recognition of the concept of quantifiable efficiency.
Smeaton had, as it happened, already applied his tech-
nique to the improvement of the performance of
waterwheels. But while this technique is important,
indeed essential, in any society with an advanced tech
nology, it cannot of itself lead to radical new depar-
tures; it can lead only to the progressive improvement
of the machine as specified and that within the limits
of the materials and auxiliary devices available.

The second notable event was the revolutionary
invention by James Watt of a practicable form of steam
engine. This followed painstaking fundamental re-
search in the new science of heat; a science to which
Watt's friend Joseph Black had contributed. Watt's
engine worked, as did Newcomen's, by condensing
steam to form a vacuum but condensation was now
carried out in a separate cylinder, or “condenser,”
which could be kept cold all the time and did not have
to be heated up once a cycle. This gave a great econ-
omy of heat and therefore of fuel; it also clarified the
idea that a heat engine works by virtue of a flow of
heat from a hot to a cold body, the cold body being
no less essential than the hot body, or furnace. Further
to reduce waste of heat, Watt used steam at atmos-
pheric pressure rather than cold air to drive the piston
in the hot or working cylinder. Finally, to obtain the
best possible economy he proposed to operate the
engine “expansively” allowing the pressure of driving
steam to fall steadily as the piston travelled down the
cylinder. In this way he sought to extract the last ounce
of “duty,” or as we should now say energy, from the
hot steam.

If the industrial revolution may be said to have
begun in one particular industry it was in that of
textiles rather than in power or mining. In 1769
Richard Arkwright was awarded a patent for the roller
spinning of cotton. Roller spinning was not a novel
idea, but Arkwright was the first to achieve it in prac-
tice. To do this the design of his machine had to satisfy
four critical requirements. It had to have more than
one set of rollers, their relative speeds of rotation had
to be correct, their distance apart had to be about the
same as the average length of the fibers (much less and
the fibers are broken, much more and the thread comes
apart), and, lastly, the pressures between each pair of
rollers had to be correct. There was wide scope for
error and therefore failure. It is to the credit of Ark-
wright that he eventually succeeded and made the
mechanical spinning of cotton, the key to the
mechanization of the textile industries, possible.

Arkwright's spinning machine, or “water frame”
stimulated the mechanization of the other textile
processes. By the beginning of the nineteenth century
every such process from the preliminary treatment of
the raw fibers to the final weaving of the threads had
been successfully mechanized and could be driven
either by water or by steam power. And all the essen-
tial inventions, from the early fly shuttle to Richard
Roberts' self-acting mule, were, in Bacon's sense,

“empirical.” Science was not involved at any stage:
the details and operations of the machines could have
been easily understood by a contemporary of
Leonardo. There is no evidence that the pioneers of
textile technology made scientific studies of fibers by
using microscopes or any other scientific devices avail-
able at that time. Furthermore, few of them bothered
to become Fellows of the Royal Society. The textile
revolution was, in short, initially based on empirical
inventions. So, too, was the new technology of indus-
trial machine tools which developed in America and
England in the first half of the nineteenth century, and
which certainly owed something in its early days to
the rapid progress of textile machinery.

The mechanization of the textile industries, and the
successful harnessing of waterwheels and early steam
engines to power such delicate processes as spinning
and weaving, constituted one of the great triumphs of
technology. It was the first instance of what is now
exemplified in the wide range of mass production
industries. As early as 1835 Andrew Ure, in the course
of a paean of praise for the new textile factories,
asserted that the essence of the system lay in dividing
the production process into stages, each of which could
then be dealt with by self-regulating automatic ma-
chinery. He underestimated the difficulties of taking
this one stage further, but his insight was nonetheless
remarkable for the time.

Science may not have been involved in the invention
of textile machinery; but it played a vital role in the
solution of the related problems of power. In England
and in France throughout the eighteenth century
increasing attention had been paid to the efficient
generation and transformation of power. In England
industrial revolution made this particularly urgent for
the best river sites for water power were quickly taken;
and, as mills prospered and expanded, even these were
found to be inadequate. The demand for power was
insatiable; the need for efficient generation was
paramount.

Inevitably, the two major power technologies tended
to converge. Techniques and devices used in steam
engines were applied to water power and vice versa:
designers of industrial waterwheels were often design-
ers of steam engines also. For a long period the advan-
tages of steam and water power were fairly evenly
balanced. But the efficiency of the steam engine was
steadily being increased and the appearance of the high
pressure steam engine after 1800 widened the field of
application to include land and sea transport and a
great range of industrial purposes. Further, it became
apparent in the first two decades of the century that
the economy of high pressure steam engines could be
increased considerably above that of low pressure en
gines. What, indeed, were the limits of efficiency of
the steam engine?

In 1824 a French engineer of genius, Sadi Carnot,
propounded a remarkable synthesis of knowledge. It
was known by then that radiant heat from the sun was
responsible for the movements of the atmosphere and,
ultimately, for the hydrologic cycle: it was also known
that heat, or rather the flow of heat, caused many other
natural phenomena. The steam, or heat engine works
by virtue of the flow of heat from a hot body, or
furnace, to a cold body, or condenser. By considering
the principles of Watt's expansive engine and by treat-
ing the flow of heat as strictly analogous to the flow
of water, Carnot was able to envisage an ideal heat
engine: one which could, from a given flow of heat,
yield enough power to restore, or recover the initial
(thermal) situation. Carnot did not consider the actual
conversion of heat into mechanical energy: he believed,
with the majority of engineers and scientists of the
time, that heat is always conserved. Although some of
his assumptions were incorrect, the basis of his argu-
ment was sound and his realization—derived from an
obvious hydraulic analogy—that the greater the “fall”
of heat, or the temperature difference over which an
engine works, the greater its efficiency, was correct.
This was consistent with, if it did not explain, the
superior efficiency of high pressure (or high tempera-
ture) steam engines and it led him to recognize the
theoretical (and the ultimately practical) superiority
of the hot air engine, a judgment which was vindicated
by the invention of the Diesel engine at the end of
the century. In fact the history of the steam engine
and of heat engines generally, must be divided into
two distinct periods, before and after Carnot.

The ideal Carnot engine may be considered, in ab-
stract terms, as marking the end of the spectrum of
all thermo-mechanical transformations in nature and
in art. In this Galilean sense, it provided the basis for
a new science—thermodynamics—which when it was
reconciled with the correct, dynamical theory of heat
proved to be as fundamental as Newtonian mechanics.
Thermodynamics is concerned with the transformations
of energy and the conditions under which they take
place. After Carnot, notable contributions were made
by Joule, Helmholtz, Thomson, Clausius, and Gibbs.
But besides its applications to sciences such as physics,
chemistry, and meteorology, thermodynamics has
influenced the development of cosmological thought.
Its implications in this respect were understood from
the beginning, but the idea of a thermodynamically
doomed universe is still plausible.

The intellectual and psychological origins of ther-
modynamics are to be found partly in the science
of heat, but mainly in Carnot's deep understanding of

the mode of operation of the Watt-type expansive
condensing engine, in the increasingly wide range of
application of steam power in the early nineteenth
century, and in the impressive amount of mechanical
work that steam engines could perform. In fact the
establishment of thermodynamics was the second oc-
casion on which a major technological advance led to
new departures in science and to a change in general
thought. As the mechanical clock contributed to the
formulation in the seventeenth century of the idea of
a “clockwork” universe, so the refinement of the heat
engine left its mark on the cosmology of the nineteenth
century.

The middle of the nineteenth century was a period
of intellectual synthesis, when electromagnetic field-
theory, the principle of natural selection, the con-
servation of energy, and the laws of thermodynamics
were all established. Since then social changes have
hastened the proliferation of science if not necessarily
its rate of progress. The recent increase in the numbers
of scientists has been accompanied by the greatly
increased application of science to the processes of
innovation. It may even be said that a new mode of
technological innovation has emerged. Applied science
laboratories, copied originally from nineteenth-century
German university laboratories, now study materials
and processes relevant to the needs of industry and
also serve as sources of scientific invention. The dis-
covery of the technique of directed scientific research
has brought developments in social organization
whereby scientific manpower can be deployed to solve
such massive problems as those of nuclear power and
space travel. The Baconian dream has, in the course
of eighty years or so, become reality. With all this there
has occurred a subtle shift in conventional ideas: the
notion of “open-ended” technology is now widely
accepted. It would be considered foolish, today, to try
to specify the limits, other than those imposed by logic,
of the possible achievements of technology.

There is evidence to suggest that during the nine-
teenth century the absolute laws of Newtonian physics,
the indestructible atoms of Daltonian chemistry, and
the “iron” laws of classical economics together with
a reasonably complete knowledge of the size, nature,
and resources of the planet constituted, between them,
barriers beyond which technological development
could not proceed. The limits were known and any
suggestion that technology might be capable of
indefinite extension would have been rejected. This has
now changed, due largely to the recent achievements
of technology and, no less, to the dissolution of the
old nineteenth-century certainties, social and eco-
nomic as well as scientific.

The impressive innovations of the twentieth century
—automobiles, air travel, communications technology,
computers, control systems, and a multitude of con-
sumer goods—have enormously improved the material
conditions of life. In other respects their direct effects
have not yet become clear although there is no doubt
that they have had a cumulative if ambiguous influence
on the commonly accepted idea of progress. Historians
have usually related the rise of this idea to the substi-
tution of social theories for religious beliefs and to the
advance of pure science. Although it is clear that
technology, too, has been concerned, this aspect has
not been studied in any detail. The time is certainly
ripe for such a study for in some quarters technology
has, today, become suspect. It is said to have put
immense destructive powers in the hands of irre-
sponsible politicians; reckless technological develop-
ments often cause pollution of the environment; tech-
nology generally is accused of debasing the quality of
life by imposing excessive specialization and an undue
mechanization of the conditions of work. But the first
two are as much the outcome of common human fail-
ings as a consequence of our inability to develop a
system of technology more in accord with Bacon's
organic precepts. The last is a product of social orga-
nization and not, directly, of technology. Indeed, there
are grounds for believing that the inventive faculty and
invention generally might be harmed by excessive
specialization.

There are, as we have seen, a number of different
modes of technological innovation. Before the seven-
teenth century inventions (empirical or scientific) were
diffused by imitation and adaptation while improve-
ment was established by the survival of the fittest. Now,
technology has become a complex but consciously
directed group of social activities involving a wide
range of skills, exemplified by scientific research,
managerial expertise, and practical and inventive
abilities. The powers of technology appear to be
unlimited. If some of the dangers may be great, the
potential rewards are greater still. This is not simply
a matter of material benefits for, as we have seen, major
changes in thought have, in the past, occurred as con-
sequences of technological advances.

BIBLIOGRAPHY

General Works. Eugene S. Ferguson, Bibliography of the
History of Technology (Cambridge, Mass., 1968). Friedrich
Klemm, Technik: eine Geschichte ihrer Probleme (Munich,
1954), trans. Mrs. D. W. Singer as A History of Western
Technology (London and New York, 1959). Joseph Needham,
Science and Civilisation in China (Cambridge, 1954-).
Charles Singer, E. J. Holmyard, A. R. Hall, and T. I.

Williams, A History of Technology, 5 vols. (Oxford and New
York, 1954-58). A. P. Usher, A History of Mechanical Inven-
tions, 2nd ed. (Cambridge, Mass., 1954; reprint 1959).

Works Relating Technology to Science and Other Social
Activities. A. C. Crombie, Augustine to Galileo: the History
of Science. A.D. 400-1650 (London, 1952); reprinted as Me-
dieval and Early Modern Science, 2 vols. (London and New
York, 1959). R. J. Forbes and E. J. Dijksterhuis, A History
of Science and Technology, 2 vols. (London, 1963). Lewis
Mumford, Technics and Civilization (New York, 1934;
reprint 1963). Lynn White, Jr., Medieval Technology and
Social Change (Oxford and New York, 1962).

Works Having Relevance for the History of Technology.
J. B. Bury, The Idea of Progress. An Inquiry into its Origin
and Growth (London, 1920; various reprints). A. R. Hall,
The Scientific Revolution, 2nd ed. (London, 1962; reprint
1957). Robert Lenoble, “La pensée scientifique,” in Maurice
Daumas, ed., Histoire de la science (Paris, 1963). W. Warren
Wagar, “Modern Views of the Origins of the Idea of
Progress,” Journal of the History of Ideas, 28 (1967), 55-70.
A. N. Whitehead, Science and the Modern World (London
and New York, 1925; reprint 1957).

Works Dealing with Individuals, Topics, or Periods.
D. S. L. Cardwell, Watt to Kelvin and Clausius. The Rise of
Thermodynamics and the Early Industrial Age (London,
1970). Sadi Carnot, Réflexions sur la puissance motrice du
feu (Paris, 1824; facsimile ed. 1953), trans. R. H. Thurston,
republished with introduction by E. Mendoza as Reflections
on the Motive Power of Fire (reprint, 1960). Carlo Cipolla,
Clocks and Culture, 1300-1700 (London, 1967). See also the
various papers by Derek J. de Solla Price and by Silvio A.
Bedini in Technology and Culture, and elsewhere. John
Diebold, Automation: the Advent of the Automatic Factory
(New York, 1952). Galileo Galilei, De motu and Le
meccaniche, trans. I. E. Drabkin and Stillman Drake as On
Motion and On Mechanics (Madison, 1960), with useful
introductions and notes by the translators; idem, Discorsi
... intorno a due Nuove Scienze (1638), trans. H. Crew and
A. de Salvio as Dialogues... Concerning Two New Sciences
(New York, 1914; also reprint). Norman T. Gridgeman,
article on Charles Babbage, Dictionary of Scientific Biogra-
phy (New York, 1970-), I, 354-56. H. J. Habbakuk, American
and British Technology in the Nineteenth Century (Cam-
bridge, 1962). R. L. Hills, Power in the Industrial Revolution
(Manchester, 1970). Thomas P. Hughes, ed., Selections from
the Lives of the Engineers... by Samuel Smiles (Cambridge,
Mass., 1966). John Jewkes, David Sawers, and Richard
Stillerman, The Sources of Invention (London, 1958). A. G.
Keller, A Theatre of Machines (London, 1964). Leonardo
Olschki, Geschichte der neusprechlichen wissenschaftlichen
Literatur, 3 vols. (Leipzig and Halle, 1919-27). L. T. C. Rolt,
A Short History of Machine Tools (Cambridge, Mass., 1965).
Andrew Ure, The Philosophy of Manufactures (London,
1835; reprint 1967). Edgar Zilzel, “Concept of Scientific
Progress,” Journal of the History of Ideas, 6 (1946), 325-49.

The main journals for the history of technology are:
Technology and Culture, and Transactions of the Newcomen
Society. Articles dealing with the impact of technology on
culture frequently appear in such journals as Archives Inter-
nationales d'Histoire des Sciences, Isis, Annals of Science,
and Journal of the History of Ideas.

D. S. L. CARDWELL

[See also Alchemy; Baconianism; Newton on Method;
Progress; Work.]