What is the analemma and how does it work?

An elongated figure 8 has been carved into the faces of the two central stones. This line reflects the path that the sun's image sweeps out a mid-day over the course of the year. The image is projected through a small hole set in a brass plate under the lintel of the south trilithon.

Figure 18. The scribed analemma on the face of the two central Stonehenge blocks.

Figure 19. Focusing aperture plate on the South Trilithon.

Just before mid-day the sun shines through this hole and the resulting image strikes the central rocks. At midday precisely, it is centered on the scribed line.

Figure 20. Sun's image as it crosses the analemma curve at midsummer.

By marking the position of the sun on the line, which is notched for every fifth day, it is possible to read what day of the year it is.

Figure 21. Analemma marks for each five day period, with the sun crossing the curve at midwinter.

Back to Top

Who thought of this idea?

This device was used by the Anasazi Indians in Chaco Canyon in New Mexico in the hey day of that culture. The Indians built a number of pueblos in the canyon, in the period from 950 to 1100 A.D. Because they had to know when to plant their crops they developed a form of calendar using the position of the sun. The annual movement of the sun around the sky, and other astronomic ideas, grew to have both a practical and a religious role both then, and, in modern times, in Hopi and Zuni culture.

At Pueblo Bonito the Anasazi used windows to limit the entry of the sun into certain rooms to only known times. Thus, for example, the sun would first enter one room about seven weeks before the winter solstice, and the beam would move about three centimeters a day. This would allow the Sun Priests time to predict the actual solstice.

Perhaps the more famous set of solar markers at Chaco Canyon is, however, the two spirals carved into a rock face at Fajada Butte. These spirals, which are less than half a meter wide, are carved behind three rock slabs, which appear to have naturally fallen into place. At the summer solstice a shaft of light, formed by the slabs, appears above the larger spiral at about 11 am. Over the next twenty minutes, it is reported by Zeilick, that the shaft of light will sink down through the heart of the spiral. At the winter solstice the light appears, instead, at the edge of the spiral. In this manner two of the important calendar days of the year can be identified.

Although this is useful, and may have a significant religious aspect, it is, not enough to provide an accurate calendar for the planting of crops, and other needs of the tribe. For this reason the other predictors, where the sun beams entered certain windows, and struck certain features within the buildings on given days within the year are more likely to have been of daily use. It is this feature, of light access to different points on different days, which Dr Senne adopted to this UMR calendar.

Back to Top

What else does the UMR-Stonehenge do?

At dawn on mid-summer morning the sun rises, as viewed from the center of the henge, over the heelstone - although this is currently hidden by St. Pat's Church. It sets that night through the northwest trilithon gap.


The sunrise occurs at around 6 am although the sun is not clearly seen for several minutes until it clears the trees that are currently covering the horizon.

Figure 22. Midsummer sunrise over the heel stone.

That evening the sun set can be viewed from the center of the Stonehenge, with the sun setting through the legs of the Northwest Trilithon.

Figure 23. Sunset behind the Northwest Trilithon, Midsummer's Eve.

On mid-winters morning, the sun rising can be viewed through the SouthEast Trilithon, and it's setting through the SouthWest Trilithon.

Figure 24. Polar window in the North Trilithon.

The box opening of the North Trilithon frames the position of the North Star when viewed, at night, from half-way between the center of the circle and the stone. This position is marked with two lights inset into the asphalt floor of the monument. The accuracy of this positioning has been calculated for the next 4,000 years.

Back to Top


When was it built?

The UMR-Stonehenge project began in 1982, when Dr. Marchello formed the organizing committee. The rock was acquired in 1983, and rock cutting started in the fall of that year. It was completed during 1984 and dedicated on the evening of June 20, 1984, the shortest night of the year, in the presence of John Bevan, white-robed Druid of the Geffodd of Druids of the Isle of Britain.

Figure 25. Druid John Bevan pronouncing the Stonehenge open

(Dr. Senne is also holding the sword, and Dr. Summers is in the background).

The modern Druids are a Society in Britain who have been formed to maintain the language and customs of Wales. They are not the religious priests who practices in England at the time of the Roman Invasion.

As part of the dedication, Mr. Bevan used the following Welsh invocation:

Dyro Dduw dy nawdd
Ac yn nawdd nerth
Ac yn nerth deall
Ac yn neall gwybod
Ac yng ngwybod, gwybod y cyfiawn
Ac yng ngwybod y cyfiawn, ei garu.
Ac o garu, caru pob hanfod
Ac o garu pob hanfod caru Duw
Duw a pob diani.

Which is the Archdruid's Prayer, followed by the call for Peace:

Y gwir yn erbyn y byd
A oes heddwch ? (Response - Heddwch)
Gwaedd uwch adwaedd
A oes heddwch ? (Response - Heddwch)
Llef uwch adlef
A oes heddwch (Response - Heddwch)

A cheese-henge decorated the following reception.

Figure 26. The UMR Cheese-henge.

Back to Top

Do the marks on the stone have any significance?

The dark and light marks on the stone are natural features exposed when the stone was cut, they have no other significance.

Figure 27. A natural mica "arrowhead" exposed when the rock was cut.

Similarly, the closing of the trilithon ring coincident with a solar eclipse at Rolla, was purely an accidental coincidence of timing.

Figure 28. Stages in the eclipse during the setting of the Trilithon ring.

Back to Top

Is the UMR Stonehenge the only one in America?

There are several other monuments in the United States which are somewhat similar to that erected at UMR. The nearest is the Woodhenge, which was built as part of the construction of the mounds in Illinois, just over the river from St. Louis, several hundred years ago. More recently, and along the lines of this monument, just after the First World War, Sam Hill (1857-1931) a railroad tycoon and businessman, sought to erect a monument to the 13 fallen war dead from Klickitat County, Washington.


He chose a site on the hills overlooking the Columbia River, about 115 miles east of Portland, Oregon. Using the English Stonehenge as his theme, he decided to use concrete rather than the local rock, which was considered to be of poor quality.

The site was dedicated, following the pouring of the altar, on July 4, 1918. The site was designed to follow the original version, as best as could be determined from scientific evidence at the time. The monument took some eleven years to complete, and required approximately 1650 tons of concrete.


In order to provide a surface closer to that of the original, the frames for the concrete pillars were lined with crumpled tin. He built his memorial out of concrete in the form of a full scale version of the original Stonehenge.

Figure 29. Concrete Stonehenge at Maryhill, in Washington State.

The monument is not an exact replica, because of the problems which arose with the local hills and the presence of the river gorge. Thus, the hills block the midsummer sunrise over the heel stone, which is considerably smaller and closer to the circles than at the original.


Unfortunately, the concrete has also started to weather severely, and up to two inches of erosion could be measured on some of the stones only fifty years after the monument was completed.

Figure 30. The altar stones at the Maryhill Henge.

Figure 31. Looking at the Maryhill heelstone (the narrow rock behind the ring).

More recently the Elberton Granite Association was commissioned to build what are known as the Guidestones. These are an assembly of rocks, which stand a total of 19 ft 3 inches high, which carry the same universal message of peace, in eight of the most common languages of man.


These are English, Russian, Hebrew, Arabic, Hindi, Chinese, Spanish and Swahili. In addition, the capstone carries part of the message in Babylonian Cuneiform, Egyptian Hieroglyphics and Classical Greek.

Figure 32. The Guidestones Monument in Elberton, Georgia.

The Guidestones are located just outside of Elberton, in Georgia. They weigh a total of 237,746 lbs, and were carved using thermal lances rather than using waterjets. The lettering was then carved into the stones to carry the various messages.


The stones themselves site on slabs which are flush with the surface, and the entire site was, when visited, located in a pasture.

Figure 33. Detail of a Guidestone showing the Spanish language, and the mounting.

The Gnomen, or Center Stone, has a small window through its center which is aligned with the Pole Star. This alignment changes over the years, so that the star will not always be in the center of the view. This is unlike the UMR Polar window, which was made large enough to retain the star position for the next 4,000 years.


At an erosion rate of one inch every thousand years, it is our hope that by that time the window will have grown to accommodate any additional size changes required.

Figure 34. The Guidestone Polar window.

In addition there have been a number of "modern" versions of Stonehenge. For example in Whitby, Ontario Canada, a sculptor Bill Lishman, has built a version of the megalith using old partially crushed cars to generate the equivalent of the stones.


The cars have been compressed to match the size of the stones in the original Stonehenge.

Figure 35. Bill Lishman and his "carhenge".

Back to Top

What will happen to this site?

The UMR-Stonehenge will be the central focus of a park where students and visitors alike may enjoy, hopefully for millennia*, a reminder of the abilities of our fathers - for remember the original was twice this size - and to accept the challenge of developing new technology for the future through this understanding of the past. It should be remembered that the original considerably outdated the Romans.

*If not the builders would be glad to listen to any complaints.

Figure 36. Modern "Romans" parading near Hadrians Wall.

In its current form the UMR Stonehenge is made up of an outer ring of four Pole Stones; a circle of stones, meant in this model for seats and known as the Sarsen Stones; the inner ring of five three-stone Trilithons and the two stones which make up the central Analemma.


It was in this form that the University received an award for one of the Ten Outstanding Engineering Achievements of the National Society of Professional Engineers. That year other awards included the Chicago Sewer System, and the Hubble Telescope.

Figure 37. Plaque awarded to UMR for this sculpture.

Over a ten year period UMR was one of only three Universities to achieve this high national honor.

It is hoped however that this will not mark the end of the development of this site. For the original site underwent several changes over the millennia of its development. One current suggestion is to add a ring of nineteen knights, to be known as the Knights of St. Ninian.

Two questions need to be answered here, why nineteen knights and who was St. Ninian.

Figure 38. Conceptual design for the addition of the Knights of St. Ninian ring.

Back to Top

Why Nineteen Knights?

This relates to the final ring of stones which were added as our ancestors at the original Stonehenge worked to develop a clock which would give them a calendar. The last ring added was the Bluestone ring and this had nineteen stones. If one multiplies nineteen by nineteen then one gets 361. If one then adds the four feast days when "time stands still" then this gives the number of days in a year.

This Hyperborean calendar would therefore be marked with the positioning of the nineteen knights of St. Ninian. The four feast days would be replaced by the Pole stones which have already been placed around the inner two rings of stone, and which would be integrated into the Knight Ring. This would therefore integrate the American and European solar clocks into the structure.

Back to Top


Who was St. Ninian?

Many people associate St. Patrick with engineering, and at UMR this is commemorated with St. Patrick's Day observances and a parade. However it is appropriate to remember that many engineering innovations were made by Scots.


And just as St. Patrick is remembered for bringing Christianity to Ireland, St. Ninian performed the same function for Scotland, and his memorial can be found at Whithorn Priory in Wigtown, Scotland. On an engineering campus it is fitting to recognize in this way the contribution that Scots have made to engineering progress.

Back to Top


Why are the faces blank?

It is intended that the sculptures be carved using high pressure waterjets, as an indication of the progress in the use of this innovative tool for 3-Dimensional sculpting, beyond the linear cuts of the surrounding stones. However UMR is internationally recognized for a number of areas, and has many re-knowned alumni and benefactors. By using the tools of these other departments it will be possible to create a remembrance for each Knight to personify a major benefactor to the University.


Since there are only 19 such knights and the monument will stand for several thousand years it will likely take a long time to find individuals who qualify for this honor. (The only probable equivalent is to qualify for additional space at Mount Rushmore).

Figure 39. Current design for the knights.

It is hoped that some design competition be held to create a design for the knights which can be carved from Missouri granite using waterjet technologies. If Missouri granite is used the two granites will provide a pleasant color contrast.

Back to Top


When is this going to happen?

As with all things this will require some financing. Hopefully a funding source can be identified to make this addition more rapidly than occurred in the case of the original model. Those interested in contributing may wish to contact either Tom Webb at c2873tew@umrvmb.umr.edu or Dave Summers at dsummers@umr.edu. Dave will also be glad to answer those other questions that he can about waterjet cutting and other matters related to this sculpture.

Back to Top



The following books and articles may be of interest to readers:

  • Piini, Ernest W. (1980), America's Stonehenge, Sarsen Press, Redwood City, CA, 30 p.

  • Hawkins, Gerald S. (1970), Stonehenge Decoded, Fontana Press, 253 p.

  • Plotts, Lois D. (1981), Stonehenge at Maryhill, private printing, 32 p.

  • Shepherd, R. (1980), Prehistoric Mining and Allied Industries, Academic Press, 272 p.

  • Noble, David G. ed (1984), New Light on Chaco Canyon, School of American Research Press, 95p.

  • Chippindale, Christopher (1983), Stonehenge Complete, Thames and Hudson, 295 p.

  • Pike, Donald G. and Muench, David (1974), Anasazi-Ancient People of the Rock, Crown Publishers, 191 p.

  • Wood, John E. (1980), Sun, Moon and Standing Stones, Oxford University Press, 217 p.

  • Balfour, Michael (1979), Stonehenge and its Mysteries, Hutchinson and Co. (Publishers) Ltd., 192 p.

Back to Top