To make sense out of the chaotic museum collections, Christian Jurgensen Thomsen, the curator of the Danish National Museum, began to classify cutting tools according to the material used to make them: stone, bronze, and iron. He then extended this classification to other materials which were found with them. This gave rise to a chronological scheme, known as the Three-Age System: Stone Age, Bronze Age, and Iron Age. Thomsen’s assistant and successor at the Danish National Museum, Jens Jacob Asmussen Worsaae, extended the Three-Age system from museum displays to the field. While this Three-Age system grew out of the museum-oriented archaeology of the nineteenth century, these designations are still used today, particularly with regard to some broad time periods in Europe.
The transition from the use of stone tools to the use of metal tools is considered by many to be a key event in human history. Actually, it was probably not a single event, but a gradual replacement of one technology with another. While the first metal tools were made from copper, copper is rather soft. As people realized that making an alloy of copper and tin—known as bronze—would create hard tools, the Bronze Age began to develop. While the use of bronze began in the Aegean area of Europe about 3200 BCE, it took about 1,800 years for the new technology to reach Ireland. About 2000 BCE, bronze technology seems to have accompanied some immigrants from what is now France to Ireland. With this, the Neolithic and Copper Age Irish farmers began to acquire bronze tools and the Irish Bronze Age emerged.
Some archaeologists generally divide the Irish Bronze Age into three periods: Early Bronze Age (2000 to 1500 BCE), Middle Bronze Age (1500 to 1200 BCE), and Late Bronze Age (1200 to 500 BCE). Others divide it into two periods: Early (2000 to 1500 BCE) and Late (1500 to 500 BCE).
Ireland has some relatively rich copper deposits and during the Bronze Age, settlements began to develop in these copper-producing areas. By 1500 BCE, the copper mines at Mount Gabriel in County Cork were in operation. These mines consist of 25 fairly shallow shafts: from 5 to 10 meters (16 to 33 feet). The copper was extracted from the shafts by lighting fires which heated the walls of the shaft. Then water was splashed on the hot walls which shattered the ore.
Once the ore had been removed from the mining shafts, it had to be melted. Melting the copper required the burning of about ten tons of dry wood to melt a single ton of copper ore.
During the Bronze Age, it is estimated that 370 tons of copper were produced in Counties Cork and Kerry. Much of this copper was exported from the island. While Ireland had copper, it was lacking in the tin which was needed in the production of bronze. For Ireland’s bronze industry, tin appears to have been imported from England.
The most common tool made from bronze seems to have been the ax. Bronze axes were stronger than those made from copper and could be used for longer periods of time without sharpening. In addition, bronze was used to make a variety of other artifacts, including daggers and awls.
During the Bronze Age, the technology for making bronze tools improved. In the Early Bronze Age, the axes were made by pouring bronze into a hollowed out stone. By the Middle Bronze Age, people were using two-part molds: two hollowed stones were put together and metal poured into the gap at the top. This allowed the tool-makers to make more complex items such as daggers. By the Late Bronze Age, people were making models out of wax or fat. Then they would put clay around the model, heat the clay and melt the wax or fat. Then they would pour in the molten bronze and, once it had set, they would chip away the clay.
During the Bronze Age the Irish population grew, which put more pressure on the land to produce food for this population. The earlier Neolithic farmers had cleared the highland forests for their farms. With the bronze axes, they were now able to more easily clear the lowland forests. The Bronze Age marks the beginning of the systematic clearing of Ireland’s lowland forests.
One of the other interesting bronze artifacts manufactured in Ireland at this time was the horn. About 120 musical horns have been uncovered by archaeologists. Some of these were almost S-shaped and were played so that the curved trumpet part was held above the head and faced the audience.
During the Irish Bronze Age, bronze was not the only metal being used: at this time there is also a great deal of work being done with gold. While gold is not particularly useful in tools, it became a highly desirable ornamental metal. It was often made into jewelry. Some archaeologists feel that the increased use of gold at this time corresponds to the development of social stratification in Irish society and the emergence of aristocracies in some communities.
Houses during the Bronze Age were similar to those used during the Neolithic: they were rectangular or circular in form. The houses were generally constructed with wattle-and-daub walls and thatched roofs. The circular houses ranged from four to seven meters (13 to 23 feet) in diameter and had a central post which supported the roof. Some of the houses were constructed from sod which was placed in a wooden frame. It was not uncommon for a house to have a circle wooden fence which would create an enclosure in front of the house.
Cooking was done outside. The Bronze Age cooking place—fulacht fian in the Irish language—was a wood-lined trough which was dug in the ground. It would be filled with water and stones which had been heated in a nearby fire would be thrown in the water. In this way, the water could be brought to a boil and cook the meat which had been placed in it. Experimental archaeology has shown that water can be brought to boil in about 30 minutes and that a leg of mutton can be cooked in less than four hours.
After cooking the meal, the broken stones would be tossed off to one side. Over time a distinctive horseshoe-shaped mound would be formed and these are still visible in many parts of Ireland today, particularly in the southwest.
During the Irish Bronze Age a number of stone circles and henges were constructed, presumably for ceremonial purposes. Henges are earthen circles which were sometimes constructed around or beside the earlier Neolithic megaliths. While the highest concentration of the henges appears to be in the Boyne Valley of County Meath, the home of the passage tombs of Knowth and Newgrange, there were also henges constructed in other parts of the island.
In constructing a henge, the people would scrape soil from the center of a large circle—100 to 200 meters (330 to 660 feet) across—to form a small ridge. Within the henges, archaeologists have found the cremated remains of animals. There were also wooden and stone posts within the henge.
One example of a henge is found at Ballynahatty, near Belfast in Northern Ireland. This henge, known as the Giant’s Ring, is a circular enclosure which is about 180 meters in diameter. It is surrounded by an earthwork bank which is about 3.5 meters high. Inside of the circle, just east of center, is a small passage tomb.
Shown above is the Giant’s Ring henge.
Shown above is the passage grave at the Giant’s Ring.
During the Late Bronze Age, stone circles begin to appear. It is assumed that these were ceremonial structures. Stone circles were built in the Sperrin Mountains of counties Londonderry and Tyrone and in the mountains of counties Cork and Kerry. In West Cork and Kerry, the circles are made up of uneven numbers of stone—from five to seventeen—and enclose an area from 8 feet to 50 feet in diameter.
Beaghmore is a complex of stone circles and cairns in county Tyrone. The complex includes seven low stone circles of different sizes which range from 10 meters (33 feet) to 20 meters (67 feet) in diameter. The stones are small with most less than half a meter in height. Six of the seven circles are paired. The interior of the unpaired circle has been filled with more than 800 small stones which were placed upright within the circle.
The stone circles at Beaghmore are shown above.
Beaghmore also has twelve cairns and ten stone rows. Each of the pairs of circles has a small cairn placed between them. The cairns frequently cover a cremation burial. The stone rows radiate out from the circles in a northeast direction.
A cairn at Beaghmore is shown above.
The stone rows at Beaghmore are shown above.
While there is some speculation that the circles were constructed to record the movements of the sun and moon and to mark the solstices, the features do not have very accurate alignments correlated to specific astronomical features.
The largest stone circle is that of Grange at Lough Gurin in county Limerick. It is 150 feet in diameter and is enclosed by 113 standing stones. The stones are surrounded by and supported by a 40-foot-wide earthen bank. The largest stone at Grange is over 13 feet high and weighs an estimated 40 tones. The circle appears to be aligned with the rising sun at the summer solstice. At this time, the sun shines directly down the center of the circle.