Orrery: A Story of Mechanical Solar Systems, Clocks, and English Nobility

By Tony Buick

“Orrery” appeals to almost anyone interested in popular astronomy, astronomical mechanical devices, scientific instruments, the history of clocks - and even the history of aristocratic and prestigious families! Many people these days – not only astronomers – have a good idea of the main components of the Solar System. They might also know about the orrery, a mechanical model that shows the movements of the Moon and planets. But not too many know why it was so named and who it was named after. The Boyle family – the Earls of Orrery –include the famous Boyle of Boyle’s Law. But others were key in the history of the orrery, not the least being clockmakers. Aware of the lunar and planetary content of the sky, they strove to make scientific instruments to demonstrate their movements and introduced measuring devices to predict their positions. In antiquity, their lives on occasion depended on the accuracy; upsetting kings and lords was dangerous business!

Orreries are found everywhere. They can be made of wood or metal, and are even available today as home-assembly kits and children’s toys. They appear in paintings, on computers, on the side of royal clocks, in stately home hallways, and of course, in museums all over the world. This book contains illustrations of orreries to give a guide as to what is and was available and where to see the best examples. It also contains information and references to help readers who want to make (or buy) their own orrery.

The story of the Boyles is not just relevant to a tiny corner of Ireland, but spans the world. “Orrery” highlights the process of discovery and humankind’s universal fascination with the heavens. Provides a fascinating example of the relationship between innovative thinking (invention) and precision engineering (execution).

• Language: English
• Publisher: Springer
• Release date: Oct 26, 2013
• ISBN: 9781461470434

Book preview

Tony BuickAstronomers' UniverseOrrery2014A Story of Mechanical Solar Systems, Clocks, and English Nobility10.1007/978-1-4614-7043-4_1

© Springer Science+Business Media New York 2014

1. Setting the Scene

Tony Buick¹  

(1)

1 Downs View Close, BR6 7SU Orpington, United Kingdom

Tony Buick

Email: [e-mail]

What Is an Orrery?

Astronomy in Ancient Civilizations

The Development of Scientific and Astronomical Instruments

Mechanical Clocks

Abstract

An orrery is a working model that demonstrates the movement of the planets, often with their moons, within our Solar System. More details of the eighteenth-century example shown in Fig 1.1 are given later.

Although the principle of making one or two spheres revolve around another seems simple by modern-day standards, the first ones were works of technical and imaginative brilliance at a time of striving for ever better micro-engineering precision. Much of the effort during the early-to mid-eighteenth century was driven by the imperative to produce the most accurate clocks for seafarers and their navigation, and some clockmakers became the orrery makers. But the first such devices were not called orreries! They were tellurions, telluriums, or planetaria. They were later named after the fourth Earl of Orrery.

What Is an Orrery?

An orrery is a working model that demonstrates the movement of the planets, often with their moons, within our Solar System. More details of the eighteenth-century example shown in Fig 1.1 are given later.

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Fig. 1.1

Example of an eighteenth-century orrery. (Photograph by the author with permission of Sir Patrick Moore.)

Although the principle of making one or two spheres revolve around another seems simple by modern-day standards, the first ones were works of technical and imaginative brilliance at a time of striving for ever better micro-engineering precision. Much of the effort during the early-to mid-eighteenth century was driven by the imperative to produce the most accurate clocks for seafarers and their navigation, and some clockmakers became the orrery makers. But the first such devices were not called orreries! They were tellurions, telluriums, or planetaria. They were later named after the fourth Earl of Orrery.

So how did nobility become involved for the tellurion to be forever labeled orrery? The names of key figures of the time, Graham, Rowley and Tompion, do not fall off the tongue lightly for most. That is even true for those familiar with ‘orrery,’ but theirs is the credit for the essential dedication and skills developed to produce the attractive and appealing instruments. On its own the model was a small development, even a sideline, in the quest for better craftsmanship, accuracy and plain showing-off. But it sits at a key point within the story of astronomy from early humans staring at the sky in wonder and curiosity with an urge to make sense of all they saw right up to the modern-day achievements of space technology and understanding.

From scientific and lay observations there is no doubt about the major structure of the Solar System; local space travel and telescopes allow remote viewing of Earth and other planets to confirm its characteristics. But there was a time when such facts were not known, and hypotheses, religious pronouncements, myths and even guesses had to be made to account for the appearance and movement of the ever-present and constantly winking dots in the sky above. It is possible that the very first time anything ‘up’ in the night sky was noticed was when our hominid species advanced to the more energy-efficient walking on two legs (bipedalism) instead of four (quadrapedalism), to take advantage of the vast savannah lands that replaced forests as climate changes took place. That would be around four million years ago, when the Australopithecus genus roamed and evolved in East Africa before spreading far and wide and then becoming extinct, but not before its branches played a significant role in the evolution of modern man, Homo sapiens sapiens .

Astronomy in Ancient Civilizations

Human curiosity and understanding had civilizations throughout the world heading in the same direction in terms of wanting to account for the movement of the stars, planets, Sun and Moon and knowing what it meant for their religions, destiny, surviving nature’s regular events and, naturally, personal power. To achieve that understanding, structures were built, simple and complex, to assist with observations and predictions. Outstanding among the ancient monuments is the World Heritage Site of Stonehenge in Wiltshire, England , which was possibly built by the people of the time of 3100 B.C. to define the summer and/or winter solstices through the alignment of particular stones with the Sun and the Moon. Possibly it was an astronomical observatory or maybe a religious monument; it might even have been a place of healing or a burial site. Recent studies suggest the possibility that the orientation of the stones was more to do with access to a river than alignment with the Sun. Figure 1.2 is from the Atlas van Loon 1649. But even earlier than this, celestial objects proved to be fascinating for the very first high cultures we know of.

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Fig. 1.2

World Heritage Site of Stonehenge in Wiltshire, England. (Credit: Image from the Atlas van Loon of 1649, Public domain.)

The wonderful and ancient names of Mesopotamia and Sumer began to emerge as archaeological evidence was unearthed dating from 5,000 B.C. onward to reveal the creation of a culture, very different from our own, building cities and forming a thinking society commonly described as the Cradle of Civilization . Mesopotamia, between the rivers, is a toponym for the Tigris-Euphrates river system corresponding to modern-day Iraq.

The earliest language used in Mesopotamia was Sumerian, and the early writing was cuneiform, or wedge-shaped, script. In fact, as early as 8000 B.C., with the development of pictograms (picture writing), records were kept—clay tokens—that eventually led to the cuneiform writing . Three wedges then a drawing of a bird meant three birds. Ten was represented by a circle. It was found by the Sumerians that wet clay could be neatly and accurately imprinted to replace scratching on stones, and since the cut reeds used as styluses best produced the shape of a triangle, or wedge, this became a basis of writing .

Cuneiform texts and artifacts that date back to about 6000 B.C. have been found in the valley of the Euphrates and are the earliest known attempts to catalog the stars and show star groupings such as the Lion and the Bull .

Baked clay was hard and very durable, hence the huge number of artifacts that have been unearthed and contributed to the collection of important archaeological evidence. Figure 1.3 shows a cuneiform tablet and the text is a list of gifts from the High and Mighty of Adab (an ancient city located in modern-day Iraq) to the High Priestess on the occasion of her election to the temple. It has clearly been written by an expert scribe.

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Fig. 1.3

Sumerian inscription on an ancient cuneiform tablet. (Courtesy of the Schoyen Collection, public domain.)

The Sumerians and Babylonians developed great skills at mathematics, astronomy and, essential for that time, astrology. Mathematics and science were based on a sexagesimal numerical system, i.e., to the base of 60 . They multiplied 60 by 10, then multiplied 600 by 6, and so on. The number 60 has the advantage of being divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30. The Sumerians also divided the circle into 360°. From these early people came the word dozen (a fifth of 60) and the division of the clock to measure hours, minutes, and seconds. Hence the 60-minute hour, 24-hour day and the 360° circle.

Since the survival of society depended so much on the seasons and natural events, it wasn’t long before scientific skills were used to predict weather cycles, river behavior and any other regular feature that affected the cultivation of crops. Of course, the Egyptians were developing scientific and mathematical awareness at the same time, from around 5000 B.C. For them it was vital to predict the annual flooding of the Nile. Both the Babylonians and the Egyptians worked with the 365-day year .

It is not unexpected that both Mesopotamians and Egyptians would look to the night sky to predict events. Stars were grouped into patterns, and their orderly appearance clearly tied in with their observations of the natural cycles of events. Models, structures, stone circles and drawings were all created to assist in the correct prediction of events and times for festivals. In many cases the astronomer’s/astrologer’s reputation and life depended on the accuracy of these predictions.

The ancient Egyptians made many great advances in science, especially in medicine and alchemy . The Egyptians also contributed to ancient astronomy and, as with the Mesopotamians, their work was based upon agriculture and predicting the seasons. Since their very existence depended on it, the annual flooding of the Nile was the foundation of Egyptian civilization and agriculture, so predicting this occurrence with accuracy and in relation to their religion was the driving force behind the development of Egyptian astronomy.

The way the Egyptians built their magnificent pyramids (in a sense, their orreries or planetaria) and accurately aligned them with stars they were familiar with is a testament to the relationship they had with the sky and its mysteries. They seemed to be obsessed with true alignment with north/south, and a plethora of studies over many years have suggested how it was achieved—from the position of the Sun and stars. Of course, it is important for modern studies to make allowances for the change in the relative positions of the stars as viewed from Earth and the various precessions of Earth since Egyptian times. The mathematical methods of the time, such as multiplication and division, involved basic empirical processes that were used by mathematicians without really knowing why they worked.

The history of science and technology in the Indian subcontinent begins with prehistoric human activity at Mehrgarh (one of the most important Neolithic, 7000–2500 B.C., sites in archaeology). Mehrgarh is in present-day Pakistan and continues through the Indus Valley. The oldest extant text of astronomy is the treatise by the Indian astronomer Lagadha, possibly dating to the last millennium B.C. or a little earlier . It describes rules for tracking the motions of the Sun and Moon. However, it was soon supplanted by the knowledge of the Greeks.

The ancient history of India is much about the Indus Valley civilization, 2500–1800 B.C., in the northwest. Many meticulously planned and constructed cities were found around the valley of the Indus River, where its people, the Harappans, evolved some new techniques in metallurgy and worked with copper, bronze, lead and tin . The engineering skill of the Harappans was remarkable, especially in building docks after a careful study of tides, waves and currents. They had their own script, the Indus Valley script, which is, as yet, undeciphered and may eventually reveal more of their secrets and science.

By the sixth century A.D. Indian astronomy and mathematics had become quite sophisticated. One of the main contributors was Aryabhata , a mathematician and astronomer who introduced the decimal point, arithmetic and geometric progressions, a method for determining the positions of the planets and the rotation of Earth on its axis. He possibly even suggested heliocentricism (where Earth and the other planets revolve around the Sun, not everything around Earth). He gave a value of π as

100 + 4, × 8, add 62,000, divide by 20,000 = 3.1416.

This was a pretty accurate value. A statue of Aryabhata is shown in Fig 1.4, although we don’t know how true to life it is as there is no known information regarding his appearance.

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Fig. 1.4

Aryabhata, an Indian mathematician and astronomer of the sixth century A.D. (Creative Commons, author unknown.)

It appears that even isolated early civilizations were developing their astronomical observation skills at about the same time as the brain was evolving, growing larger, and becoming more complex. The Chinese believed that the objects and happenings in the sky were linked to their destiny and almost every dynasty from the sixteenth century B.C. to the nineteenth century A.D. retained its official astronomer to observe and record changes in the heavens. Because of this there is a huge legacy of observational facts, most of which have been verified as accurate.

One early and tantalizing observation was that the Sun sometimes became much dimmer, and there was concern that the brightness might not return. So, meticulous records of time and size of the shadow were maintained. The earliest solar eclipse record that has been verified appears in a bone inscription dating back to the Shang dynasty, which ruled in the Yellow River valley in the second millennium B.C. Studies have proved that the solar eclipse recorded there actually took place on May 26, 1217 B.C., thus also proving that it was the first reliable record of an eclipse people ever made .

Records of lunar eclipses, however, date back to an even earlier time. Bone and tortoise shell inscriptions record five lunar eclipses that took place during the fourteenth and thirteenth centuries B.C. It is possible that the earliest records of sunspots were made by the Chinese in 28 B.C. Even a record of a solar prominence has been found inscribed on tortoise shell. Other observations within the records include novae, supernovae and comets, notably one that later became confirmed as Halley’s Comet .

In spite of all the early Asian awareness of astronomy it is surprising that they maintained their belief in a flat Earth until introduced, by westerners in the seventeenth century, to the concept of a round one. This is a good example of the early isolation of civilizations and eventual exchange of information (theft?) and ideas.

It is amazing that so much brilliant science, mathematics and astronomy was spawned in the early civilization of Greece in spite of constant wars, internal and external. The highly organized culture of the Mycenaeans existed until around 1200, when it disappeared either by natural catastrophe or conquest possibly by the Dorians (Dorian is a term invented by historians to refer to that time) .

This period was followed by the Dark Ages, 1200–800 B.C., so called partly because of the dearth of information and evidence to describe the period. There was huge economic growth from 800 B.C. , resulting in an explosion of the size of families. Fighting continued between factions or from outside until around 510 B.C., the start of democracy, when it was decreed that all citizens should share in the political power. However, battles continued: the Battle of Marathon (490 B.C.); the Greco-Persian wars that continued until 449 B.C.; the Peloponnesian War, 431–404 B.C.; the Corinthian War, 395–387 B.C.; and so on for centuries. In spite of this, scientific and astronomical intellectual giants flourished such as Pythagoras, Archimedes and Hipparchus, who made enormous contributions to the development of understanding of the natural world.

On the American continent the Mayan civilization ranked highly among the Meso-American (the strip of land between North and South America) societies in astronomy. They were broadly aware of the cycles of the planets, and they especially studied the Sun, Moon and Venus, the morning and evening ‘star.’ Many buildings were aligned to act as observatories . It is possible that the Maya were the first to describe the Orion Nebula as being a blur, not a pinpoint star, before the advent of telescopes, and they could predict eclipses and transits .

The Mayan writing was, possibly, the earliest fully formed script that contained over 1000 glyphs—individual meaningful writing marks. The Mayan community at its peak of development spanned from A.D. 250–900, after which it collapsed for as yet unknown reasons. Perhaps, sadly, they are most famous for predicting the end of the world to be about December 21, 2012, which has been clearly proven wrong—you are reading this after that date! Proponents of the prediction claim its failure was because of confusion over the projections, assumptions and misunderstandings of ancient American texts.

The oldest known civilization on the South American continent is the Caral Supe (3000–2500 B.C.), located off the coast of Peru . And there were others, such as the Olmec (1200–400 B.C.) who constructed the first pyramids in the Americas; the Zapotec (500 B.C. to A.D. 750), known for its astronomical observatory building, the Nazca civilization (A.D. 1–700), famous for being (possibly) connected to huge geoglyphs (motifs in stone) found in the area, and other later ones such as the Incas (A.D. 1250–1532) and the Mississippian horticulturalists (A.D.1100–1450). Figure 1.5 shows the Meso-American Zapotek pyramid on Monte Alban .

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Fig. 1.5

The Meso-American Zapotek pyramid on Monte Alban. (Courtesy of Matt Saunders, Creative Commons Attribution-Share Alike 3.0 Unported license.)

Ancient Rome goes back to at least the eighth century B.C. , when it began to develop across a trade and traffic route by the river Tiber in Italy. A significant contribution to observational science and astronomy of the Romans was their development of the calendar, modifying that previously used by the Mesopotamian civilization. Claudius Ptolemy (A.D. 90–168) was a Roman citizen of Egypt who wrote in Greek . He is most noted in astronomy for his huge treatise The Almagest, that was very useful in many ways, but he is infamous for holding back progress by insisting on his geocentric model for the Sun, Moon and planets.

The Development of Scientific and Astronomical Instruments

To say it was a surprise would be the understatement of the millennium! In 1900–1901 underwater divers were searching for sponges off the coast of a small Greek island, Antikythera , which sits between two other islands, Kythera and Crete. They found, along with sponges, artifacts from a sunken wreck off Point Glyphadia. What they retrieved from the sunken cargo ship, possibly on its way to Rome after looting the island, staggered the scientific community—and the world!

Among the statues and pots a rock was noticed with a gear wheel embedded in it. This was believed to be a clock mechanism and was ignored until 1951 when an English physicist, Derek J de Solla Price, examined it and concluded it to be an astronomical device dating from 150–100 B.C. With its 72 gears, 3 dials, and many inscribed scales, it demonstrated skills of engineering miniaturization and complexity not seen until more than a millennium later.

Following intense interest and study, the device appears to be the first analog computer, the purpose of which was to calculate the positions of the Sun, Moon and possibly all of the five then known planets as well as to tell the date and predict eclipses. The dials are marked with the Greek signs of the zodiac and the days of the year (Egyptian calendar), even allowing for the additional day every four years. This was about a century before the additional days for leap years were inserted in the Julian calendar. It has been suggested that the instrument, dubbed the Antikythera mechanism, shown in Figs. 1.6 and 1.7, might have been created by the great ancient astronomer Hipparchus. The find poses many questions.

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Fig. 1.6

Antikythera mechanism, front view. (Courtesy of Creative Commons Attribution-Share Alike 3.0 Unported license.)

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Fig. 1.7

Antikythera mechanism, rear view, revealing some of the finer tooth gears. (Courtesy of Creative Commons Attribution-Share Alike 3.0 Unported license.)

The Babylonians are credited with the first astronomical observations and writing and there is plenty of evidence that there was an ever-increasing awareness of the planets and their periodicities. The Venus Tablet of Ammisaduqua (King Ammisaduqa, ca. 1582–1562 B.C.), written in cuneiform, refers to observations of the rising and setting of Venus . The ancient Egyptians precisely aligned their pyramids with stars . The Greeks of the time developed highly sophisticated mathematics and built simple models to discuss geocentric or heliocentric theories, and other civilizations were also on the same academic path. But there was nothing like the Antikythera mechanism, or at least nothing has been unearthed so far, although it would be unexpected if this advanced mechanism were the only one of its kind.

The geared rock and associated artifacts are housed in the Egyptian National Archaeological Museum. Many detailed models have been produced to enable its suggested full working mechanism to be viewed.

Poking a stick in the ground and watching the change of position of its shadow could be called an astronomical instrument, and probably happened a few thousand years B.C. But place the stick at an appropriate angle and it becomes a sundial, the earliest examples of which are probably the ancient Egyptian and Babylonian obelisks and shadow clocks. The Roman writer and architect Vitruvius (ca. 80–15 B.C.) listed dials and shadow clocks known at that time . The ‘Vitruvian Man’ is a famous drawing by Leonard de Vinci, made after studying Vitruvius’s notes to illustrate the ideal proportions of the human body, shown in Fig. 1.8 .

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Fig. 1.8

Vitruvian Man, drawn by Leonard de Vinci to illustrate the ideal proportions of the human body. (Courtesy of Luc Viatour, http://​en.​wikipedia.​org/​wiki/​File:​Da_​Vinci_​Vitruve_​Luc_​Viatour.​jpg.)

In antiquity, sundials were made of stone, limestone, marble, glass, wood, string, tortoise shell, ivory with iron nails, silver, gold, pewter, bronze and other metals. Leather was used to make the pouches that carried the smaller portable models. They were made all over the world including the Middle East, Mexico, Europe, Africa, Australia and America. The beauty and complexity of a seventeenth-century German ring dial (Fig. 1.9) made from ruby, gold and rock crystal and conserved in the British Museum, is illustrated with the description that reads Horizontal compass dial; set in gold ring; shoulder and sides of bezel chased with enameled scrolls; oval locket bezel; lid set with ruby surrounded by five crystals; compass inside; marked as horizontal sundial; holes for insertion of string gnomon.

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Fig. 1.9

Seventeenth-century German ring dial. (Courtesy of the Trustees of the British Museum, London.)

Sundials can be large landmarks or even memorials, such as the Kentucky Vietnam Veterans Memorial (Fig. 2.​5) . The gnomon, the stick bit that casts the shadow, is 14.62 ft above the surface and 24.27 ft long. As the shadow moves during the day it passes over the 1,103 Kentuckian names of the fallen. That must be a very emotional sight for many. Sundials may be associated with significant national history. An Australian dial, ca. 1837–1839, made by colonial engraver Raphael Clint and owned by the transported convict Daniel Cohen, has been purchased for placement in the Port Macquarie Historical Museum collection. It is a rare surviving metal object associated with penal settlement (Fig. 1.10).

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Fig. 1.10

Kentucky Vietnam Veterans Memorial. (Courtesy of Creative Commons, Public Domain.)

Sundials come in all sorts of designs; horizontal, vertical, pocket, polar, reclining, spherical, cylindrical and more. Add a curved strip with a slit in the style part of the gnomon and the equatorial bow sundial begins to look like an armillary (Fig. 1.11). Sundials of the sixteenth to eighteenth century were particularly ornate, often made of brass, and were finely marked to determine the time, such as the two shown in Figs. 1.12 and 1.13. Figure 1.12 clearly shows the maker, R. White Fecit, and the date 1732, when dials were still being used to check