A History of Engineering in Classical and Medieval Times

Donald Hill

• Publisher: Routledge
• Year: 2013
• ISBN:
  9781317761563
• Edition: 1
• Topic: History
• Subtopic: Ancient History
• Index: History

It is impossible to understand the cultures and achievements of the Greeks, Romans, Byzantines, and Arabs, without knowing something of their technology. Rome, for example, made advances in many areas which were subsequently lost and not regained for more than a millenium. This is a knowledgeable yet lucid account of the wonderful triumphs and the limitations of ancient and medieval engineering. This book systematically describes what is known about the evolution of irrigation works, dams, bridges, roads, building construction, water and wind power, automata, and clocks, with references to the social, geographical, and intellectual context.

1

Introduction

The Background

A reference framework is required in order to locate events in time and space. With some contractions and omissions, Figure 1.1 shows the conventional divisions for the classical and medieval periods. Even before the birth of the idea of nationality, it is quite acceptable to refer to specific countries, such as Greece and Italy, whose boundaries are well defined. It is also usual to refer to areas in which there is felt to have been some degree of cultural unity — for example, the Roman Empire and Islam. Sometimes space and time are embraced by one image: the Roman Empire can mean either the first four centuries of our era or the area under Roman dominion. Used with care, these concepts have value for some historical purposes, but they can be very misleading. In the first place, we have to bear in mind the shifting of frontiers; in AD 750, for example, the Iberian peninsula was predominantly Muslim while Asia Minor was Christian — by 1450 the reverse was the case. Also, and this can be more serious, the conventional divisions are associated most closely with political and military realities, and often have little bearing on intellectual or social activities. When we think of Roman literature, the names of Tacitus, Virgil and Horace come to our minds, but in the richer, more populous East the languages were Greek, Syriac, Coptic and Aramaic. Most of the literary and scientific writings, in the eastern part of the Roman Empire, were in the first two of these languages. There can be no doubt, however, that the Roman period has distinctive features that justify its special place in history. The Romans were pre-eminent in the fields of organisation, administration, public works and domestic comfort. Their standards were not equalled in these respects until the nineteenth century.

Figure 1.1: Cultural Divisions

According to convention, the Hellenistic Age began with the conquests of Alexander and ended with the death of Cleopatra. It therefore lasted for about three centuries — from about 330 BC to 30 BC. During this period the Seleucids ruled in Syria, the Ptolemies in Egypt. It is often regarded as a period of stagnation, or even regression, between the glory of Greece and the grandeur of Rome. And this for an age that produced Archimedes, Theocritus and many major engineering works! There is, in fact, a strong case for prolonging the Hellenistic Age, for want of a better name, through the Roman Empire into Byzantine times and up to the advent of Islam. In the first centuries of our era great scientists such as Ptolemy, Pappos and Hero wrote in Greek in Alexandria, and there was also a thriving scientific tradition, with Syriac as its language, centred on Harran in northern Mesopotamia. Scholars from Harran were a seminal influence on the nascent science of Islam.

The concept embodied in the term ‘Dark Ages’, however, has some validity. The period from the fifth to the eighth century witnessed a marked decline in intellectual activity, and a falling off of standards in sanitation, water supply, communications and domestic comfort. The obscurity of the period is a serious drawback for historians, since the lack of written records means that for most subjects the only evidence comes from scanty archaeological findings. In the Byzantine and Iranian Empires, in this period, civilisation remained at a high level, but written evidence from these two cultures is very sparse. In 915 al-Mas‘ūdī saw a large book dealing with the history of the Sasānid kings and many of the sciences. The book was found in the royal treasury in Persepolis in 731 and was translated from Farsi into Arabic for the Umayyad Caliph Hishām bin ‘Abd al-Malik.¹ No copy of this work has been found, but the reference to it implies that there was intellectual activity in Sasānid Iran. Indeed, we have firmer evidence for the existence of a scientific tradition in Iran in the foundation of a famous hospital and medical school in the city of Gondeshapur in Khuzistan. The transformation of Gondeshapur into an important medical centre was due to a group of Nestorian Christians from eastern Anatolia who had fled from Byzantine persecution. This probably occurred in the reign of Khusraw I (AD 531–79). Although there may have been some Indian influence, the teaching and treatment, which was based solely upon scientific medicine, was derived from the schools of Alexandria and Antioch, but it became more specialised and efficient. Gondeshapur was to be the foundation of Islamic medicine in the eighth century.² There are more written records from Byzantium than from Iran in this period, but many of these deal with theological and philosophical matters. For neither area, in fact, — and this applies to Byzantium in the centuries after the rise of Islam — is there much data about technology.

The Arab conquests of the seventh and eighth centuries changed much, particularly in the close cohesion of religion and daily life that is characteristic of the Muslim religion. The success of Arabic in replacing the original languages throughout North Africa and most of the Middle East, and becoming the vehicle for literature in the whole of the Muslim world was of tremendous importance in the upsurge of intellectual activity that began when the process of conquest and consolidation was complete. A further impetus was the translation from Greek, sometimes through the medium of Syriac, of many scientific and philosophical works. The conquering armies from Arabia were, however, small in numbers compared to the populations of the conquered lands, and a slow process of fusion took place, with Islam and Arabic becoming predominant while the Arabs were influenced by the cultural traditions of the conquered peoples. When, in the present work, the word ‘Islam’ is used, it is to designate the cultural area that was the result of this fusion. It is necessary to bear this definition in mind, since many of the great writers in Islam have been non-Muslims. In some ways the term ‘Arabic’ is more satisfactory, but it leaves out of account, for example, the great literary works written in Farsi. Also, in discussing technological matters, we often have recourse to non-literary evidence. We can hardly call a mill built in Central Asia an ‘Arabic’ mill.

The standard of technology at any time depends mainly upon the demands of society. Where there are large urban communities to be fed, housed, clothed and provided with the raw and finished materials for commerce, we shall find technology applied to agriculture, communications and industry. The Arabic writers on geography in the tenth century describe a society in which the range of foodstuffs, the quality of textiles and indeed the standard of living in general were far in advance of conditions in Europe, and utilitarian technology was therefore relatively more developed. Courtly circles in Islam, not only in great centres such as Baghdad and Cordoba, but also in the courts of minor princelings, expected to be amused and given aesthetic pleasure by the production of ingenious devices, thus stimulating the development of fine technology, despite the apparent triviality of some of the devices. A further stimulus was provided by the requirements of astronomers for timepieces and for observational and computational instruments. (Astronomers, in fact, often made their own instruments.) Conditions were not propitious in Europe at this time. Populations were scattered in small communities and the ruling classes were largely illiterate. In the twelfth century European technology began to develop rapidly, along with the growth of cities and mercantile activity. In some fields, but not all, Europe had surpassed Islam by the close of the fifteenth century. The debt owed by Europe, in matters of technology, to Islam and other civilisations has never been fully acknowledged, and it is hoped that some of the material in this book will help to redress the balance. Nevertheless, it is undeniable that European technology has continued to develop from its medieval origins until the present day, while that of other cultures has not.

A close study of the interactions among technology, society and economic life is beyond the scope — and indeed the purpose — of this work. From time to time, however, connections will be indicated when these have a direct bearing on engineering developments. For example, the use of very large mills to grind corn for Baghdad is directly related to the fact that the population of the city, about 1.5 million in the tenth century, was a large net consumer of agricultural produce. It will also become evident that in certain places at certain times there were marked expansions in engineering activity, either in the scale of installations or in innovativeness, or both. We can identify the most significant of these:

Hellenistic world	330–30 BC. Machines, fine technology, irrigation.
Sasānid Iran	200 BC–AD 640. Civil engineering, irrigation.
Roman Empire	First four centuries AD. Civil engineering, surveying, water supply.
Islam	Ninth to thirteenth centuries AD. Water supply, irrigation, water power, fine technology.
Europe	Twelfth to fifteenth centuries (and beyond). Wind and water power, machines, mechanical clock.

Engineers and Artisans

The modern idea that the engineer is essentially an applied scientist simply does not hold water. It is true that in the last two centuries the engineer has had at his disposal a growing array of quantified scientific data upon which to base his designs, and that no engineer worthy of the name can ignore these data. Nevertheless, the execution of a construction project poses a number of problems that are unconnected with pure scientific reasoning. Some of these problems are not even of a directly technical nature: for example, the financial side of contracting and subcontracting with the accompanying measurement and valuation procedures. There are many other problems that are technical, but not directly related to science. An engineer needs to know the capabilities and limitations of men, machines and materials, and the restraints imposed by weather and soil conditions. Engineering science can assist in the resolution of some of these problems, but in the end we should expect our engineers to get their hands dirty — in the workshop or on construction sites. We should not be complacent, and assume that we have got the mixture of theory and practice exactly right. There have been enough failures in modern engineering to teach us a little humility. One might object, with some justice, that we approach the structural limits of materials much more closely than did the early engineers. So we should — with 4,000 years of their experience and almost two centuries of scientific analysis behind us!

In general, the classical and medieval engineers did not have a quantified, scientific basis for their designs. An exception to this statement is the case of the five simple machines — lever, wheel, pulley, wedge and screw. Mathematical analysis of these machines had begun to take shape among the Greeks of the fourth century BC. Their results were by no means wholly theoretical. It is worth quoting in full what Bertrand Gille has to say about the greatest early worker in this field:

Archimedes of Syracuse (c. 287–212 BC), greatest of all the ancient exponents of mechanics and one of the greatest mathematicians of all time, was the first of the long line of those who have promoted science by propounding practical and definite problems. Like Pythagoras and Archytas, like the Egyptian and Babylonian surveyors before him, and like Leonardo and Galileo after him, Archimedes was a geometer because geometry is a technician’s science. His researches on statics revealed the fundamental principles relating to the lever and the centre of gravity. His studies were of great assistance to those who sought to construct purposeful machines. These geometrical investigations of Archimedes were important, since, if we may believe Plutarch (c. AD 46–c. 125), they enabled him to calculate, for example, the number of pulleys needed for lifting a given weight with a given force. He knew how to calculate mechanical advantage, than which there is nothing more important for all lifting-devices.³

There can be no doubt that the results of Archimedes and his successors such as Hero of Alexandria (fl. middle of first century AD) were applied to lifting devices, war machines,...

Table of contents

• Cover Page
• Half Title Page
• Title Page
• Copyright Page
• Contents
• Plates
• Figures
• Dedication
• Abbreviations
• Acknowledgements
• Preface
• 1. Introduction
• Civil Engineering
• Mechanical Engineering
• Fine Technology
• Bibliography
• Index