Frequently Asked Questions

Answers and Research Provided by Dr. David A. Summers


The three rings of stones which make up the Missouri S&T-Stonehenge were inspired by a monument created in Southern Britain some 5,000 years ago.  This original Stonehenge stands on a hillside about 8 miles north of the town of Salisbury.  It was begun, archaeologists now believe, as a simple device by which the seasons could be foretold, using the position of the moon, relative to four stones and a ditch.  This had become necessary at that time since the local tribes had changed from hunting to farming as a way of providing food and needed a means of telling when they should plant their crops.  There is, however, some variation in the path of the moon over the sky, from year to year, so that this first attempt at a calendar was not very accurate.  Additional stones were added over the centuries to form complete circles, around a central altar stone, as the leading shaman or priest-equivalent (this was long before the Druids) tried to make a more accurate calendar.  It was not, however, until the site was changed from marking the position of the moon to that of the sun that the "calendar" finally became accurate enough to pinpoint exact dates.


By this time the importance of the site had been shown by the use of very large stones to form two of the stone circles.  It is these two circles, the outer sarsen ring, and the inner trilithon ring which are the features most people consider when they talk of Stonehenge.  The outer of the two rings comprises 30 upright stones which stood 15 ft high was capped by a set of lintels notched to fit on the uprights and arranged to form a continuous walkway around the top of the stones.


Within this ring the 5 trilithon (three-stone) ring stands, around the altar with the highest, or great trilithon, located behind the altar and standing some 28 ft high.  Less prominent, but more necessary to tell the time between the major days when the sun shone in alignment with the great stones, a smaller bluestone ring of single stones was erected.  There were 19 of these and it is likely no coincidence that 19 multiplied by 19 equals 361 which, if one adds 4 days for fasting, celebration and recovery to mark the end of the year, gives us a calendar.  There is a reference in some of the ancient Gaelic legends to days "when time stands still."  (The Bahai faith has also, quite independently, developed such a calendar.)  An alternative explanation has been proposed by Gerald Hawkins, who suggests that these nineteen stones are related to the 18.61 year cycle during which the moon-rise position will oscillate along the local horizon.


This then, very simply, was the basic model from which the Missouri S&T-Stonehenge idea was developed.  The word stonehenge itself means "hanging stone" (for more information see bibliography) from the lintels that cap the rocks.


The Missouri University of Science and Technologyis a leading University in engineering, computer science and mining technology.  When Dr. Joseph Marchello became Chancellor, he came from the University of Maryland, where he had helped found the Center for Archaeo-Astronomy.  This interest, and the unique combination of expertise at Rolla, especially that of Dr. Joseph Senne (then Chairman of Civil Engineering and a local astronomer) and the Missouri S&T high pressure waterjet group, led him to propose construction of the project to the alumni, who funded it.

The Missouri S&T-Stonehenge is made of granite which was quarried in Elberton, Georgia.  The rock is a hard igneous stone, which is commonly used for monuments.  Elberton, Georgia is a major center of the American Granite Quarrying industry.  This happened partially because, in 1978, the National Science Foundation funded a study to find better ways of quarrying granite in the United States.  One of the ways that were tested was through the use of high pressure waterjets and Dr. Summers of the Missouri S&T RMERC was one of the panelists who worked on that program.

It is interesting to note that one of the quarries in which the original testing of waterjetting was carried out in 1978, later served as the source rock for the granite which forms the Missouri S&T Stonehenge.  The work was subcontracted from the Elberton Granite Association to Georgia Institute of Technology.  Missouri S&T carried out a field demonstration for this consortium during the week of November 27, 1978.  Cutting rates of almost 24 sq.ft./hour were achieved in the overlying "sap" stone, and a slot was cut some 18 ft long and 42 inches deep.  In the solid higher quality stone cutting rates were around 12 - 15 sq.ft./hour.

At the time that the monument was being planned the only granite quarry in Missouri was closed, and we were unable to negotiate to obtain rock from this site.  Although we received considerable help from the Missouri Department of Natural Resources, we were unable to find an alternative site from which we could economically have obtained the rock.

How the original stone was cut:

The original Stonehenge is made of varieties of sandstone rock.  This rock has a clear bedding plane to it, so that it can be relatively easily split to form flat surfaces.  Mining in Britain had been going on for at least a thousand years before Stonehenge was built, so that skilled miners would know how, using round stone hammers (still remaining at the site) flint chisels and deer antlers, to shape the stone.  Final carving to shape was probably done by manually chipping the rock, after the rocks had been moved into their final position.  We surmise this from the evidence of tools which were found at the site.


The stone cutting methods we used:

  • The rock for the Missouri S&T-Stonehenge was originally quarried by two methods, one of which is not that much different from the original.  In this method a set of wedges is placed into a line of holes along the line of break wanted.  The wedges are then hit, in turn, with a hammer and, in a short time, enough force builds up along the line that the rock breaks.
  • When cuts must be made across the bedding, splitting won't work and the rock was cut out using a flame cutting torch, something which looks like but is much bigger than a normal oxy-acetylene torch.  These lances are up to 10 ft long, and can cut the granite at about ten square feet of rock an hour.  They are very noisy and are now being replaced in quarries by diamond impregnated wire cutting saws.
  • In modern quarrying the rock is broken out from the solid in large blocks which are then split into smaller pieces by line drilling.  At the time that the rock was quarried for our Stonehenge, however, this practice was not common, and the rock which we received was not cut into the more regular shapes which are now produced from most quarries.  Those earlier methods left the rock which we received in Rolla in a ragged shape.
  • Once the rock was brought to Rolla a then novel method of mining, pioneered at Missouri S&T, was used to cut the rock.  Water was pressurized to 15,000 psi (7.5 tons to the square inch) and forced through a cutting lance fitted with two small holes, each about 0.04 inches wide (about the size of the wire in a paperclip).
  • These jets are spun, at a speed of 180 rpm and the whole cutting assembly moves over the rock at a speed of 10 ft/min.  As the jets hit the rock, they cut a slot between a quarter and a half inch deep and two inches wide.  The cutting lance is then lowered this amount, and moved back over the slot.  A frame was erected at the Rock Mechanics and Explosives Research Center to cut the rock.  It was assembled from wooden ties and radio antenna mast sections and provided a base along which the cutting lance was moved.  A wire mesh screen was fitted around the frame to protect the operator from the small pieces of flying rock which were removed by the jets during the cutting process.  The cutting lance was pulled along the frame using a bicycle chain, and two small hydraulic motors were used, one to turn the nozzle assembly, and the other to draw it along the rock surface.  During the course of the rock cutting the jets were able to cut an average of sixteen square feet of rock an hour.  The generator used to power the entire operation used between four and six gallons of fuel an hour.
  • In this way a relatively straight cut can be made on the rock surface without further damage to the rock.  You can see the lines left by individual passes of the jets on some of the rocks.
  • The base of the analemma stone was left partially uncut so that future generations could see how it was done (although it is buried under the current ground level).  The lower analemma stone sits on a concrete pad and has two slots in its base, so that it can be re-leveled if necessary.  The organizing committee felt that this was an important consideration, when it is recognized that Missouri contains a fault at New Madrid which caused one of the largest earthquakes in recorded American history.  It will be easier to re-align the smaller analemma blocks, rather than the trilithons, after the next such earthquake.
  • Missouri S&T-Stonehenge is the first major structure to be carved using high pressure waterjets, it marks the transition from mechanical excavation of rock to hydraulic excavation and thus is a major mining milestone.
  • The monument was carved by a group now known as the High Pressure Waterjet Laboratory within the Rock Mechanics and Explosives Research Center at Missouri S&T. Under the overall direction of Dr. Summers the day-to-day work was supervised by Dr. Marian Mazurkiewicz and carried out largely by a group of undergraduate students. The rock was moved around during the cutting process using a crane.


Waterjets used to trim Stonehenge block

*Showing the jet arrangement, raised after a side had been trimmed so that the jets could be seen.

Normally with the jet in the cut there is little to show the cutting action.


How the ancients did it:

The rocks for the original Stonehenge were brought anywhere from 20 to 200 miles to the site.  Contrary to popular myth, it is unlikely that vast teams of men hauled the rocks all the way.  While it would take some 700 men to pull one rock a mile a day, oxen of that period could pull between 1,200 and 4,00 lbs. each a distance of 20 miles a day- so, that a span of 15-50 animals could have made the transport much easier and quicker (Rodney Castelden noted in “The Making of Stonehenge” the rocks were likely hauled into place with oxen, which might be why the roads are so wide).

oxen pulling stone for stonehenge

Oxen hauling stones to the site (Rodney Castleden ibid)


The rocks would then be raised up a ramp and lowered into position.  By sharpening the bottom of the stones a little, it was then possible to "walk" them into their final position.  Final carving to exact shape was completed after the stones had been erected.


How Missouri S&T did it:

For Misouri S&T-Stonehenge, the rocks were brought to Missouri S&T by truck and rail.  They were carved to shape at the Rock Mechanics and Explosives Research Center and then brought to the site by truck.

It took over four hours to get each rock accurately aligned.  The Great Trilithon Ring is set on an 18 in. thick concrete pad and each rock was set on this.  Straps were tied around the center of each Stone to lower them into place, and they were then held in position using wooden braces until they could be accurately aligned and set in the concrete.  Wedges were then driven under the smaller stones (shims had to be set under the larger ones after lifting it with the crane) until they were level.

For the Analemma Stones where accuracy is critical, the rock angle was first measured, (it was 89.5 deg) and to ensure accuracy, 3 pins were set between the two rocks, while a shim 1/16 in. thick was placed under the back of the upright Stone.  The upright was set the first time it was placed.  The gap between the Stones was then sealed with resin.

Each Rock was aligned by Dr. Senne who used the Missouri S&T computer to accurately identify the position of the stones.  Each Stone was set, in turn, on the 18 inch thick concrete slab, which runs underneath the entire assembly of the five main Trilithons.

Another 18 inches of concrete was then poured around each stone to hold it in place, and wooden scaffolding was used to hold the rock in place until the concrete was set.



The Analemma is the enlogated figure 8 that has been carved into the faces of the two central stones.  This line reflects the path that the sun's image sweeps out  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.

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

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.


  • At dawn on mid-summer morning the sun rises, as viewed from the center of the henge, over the heel stone - 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 currently covering the horizon.
  • 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.
  • On mid-winters morning, the sun rising can be viewed through the Southeast Trilithon, and its setting through the Southwest 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.

The Missouri S&T-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 year), in the presence of John Bevan, a white-robed Druid of the Gorsedd.

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 practiced in England at the time of the Roman Invasion.

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

Lead with *Arch Druid's Prayer*
  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.

Followed by *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)

Dedication Speakers at S&T Stonehenge
Speakers at the Dedication: Dr. Joe Senne – who designed the megalith;
John Bevan – Druid; Dr. John Carlson – from the Center for Archaeoastronomy;
Dr. Joseph Marcello – Chancellor.

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


Similarly, the closing of the Trilithon Ring concurring with a solar eclipse at Rolla, was purely an accidental coincidence of timing.

There are several other monuments in the United States which are somewhat similar to that erected at Missouri S&T. 

The nearest is "Woodhenge", which is located over the river from St. Louis in Collinsville, Illinois. "Woodhenge is the site of a circle of posts once used to make astronomical sightings and stands west of Monk's Mound at Cahokia Mounds State Historic Site. Woodhenge is the site of five different circles that were constructed by the Native Americans that occupied the site from 900-1100 C.E. The third circle (1000 C.E.) was reconstructed in 1985 at the original location. The circle is 410 feet in diameter, had 48 posts spaced 26.8 feet apart (9 are missing on the west side, removed by a highway borrow pit)." -

More recently, and along the lines of this monument, Sam Hill (1857-1931) erected the Memorial Stonehenge near the town site of Maryhill, Washington.  "Erected as the nation’s first WWI memorial and dedicated in 1918 to the servicemen of Klickitat County, Washington, who died in the service of their country during the Great War, Hill’s Stonehenge Memorial is a monument to heroism and peace." -


There have been a number of "modern" versions of Stonehenge as well, like the one in Alliance, Nebraska.  "Carhenge", which replicates Stonehenge, consists of the circle of cars, 3 standing trilithons within the circle, the heel stone, slaughter stone, and 2 station stones and includes a “Car Art Preserve” with sculptures made from cars and parts of cars.  Located just north of Alliance, Nebraska, Carhenge is formed from vintage American automobiles, painted gray to replicate Stonehenge.  Built by Jim Reinders as a memorial to his father, it was dedicated at the June 1987 summer solstice." -

The Missouri S&T-Stonehenge will be the central focus of a park where students and visitors alike may enjoy, hopefully for millennia.  As a reminder of the abilities of our fathers -for remember the origianl 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 orginal considerably outdated the Romans.

In its current form, the Missouri S&T Stonehenge is made up of an outer ring of four Pole Stones; a cirlce 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.

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.

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

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

Castleden, Rodney (1993), "The Making of Stonehenge", Routledge-New York, 322 p.

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

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

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

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

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

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

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

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

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