The Magdeburg Hemispheres
by Deb Pierce
published in The Draft Horse Journal, Summer 2004

Miscommunication and a passing thunderstorm marred the practice session, but eventually it got sorted out and the greys of Robert Sparrow’s and the blacks of Brad Schreiber’s were finally attempting to do the impossible, namely pull the two hemispheres apart.

Tell me...would you do this? You have been asked to participate in the reenactment of a scientific experiment in which you are to hook two eight-horse hitches to opposite sides of a large metal sphere and ask them to pull-off against each other. Now understand that this sphere is comprised of two hemispheres held together only by air pressure. You have been told that if the horses succeed in pulling the hemispheres apart there will be a huge popping noise as the vacuum inside the hemispheres implodes.

Would I do this? No! Would I go watch? Absolutely!

On Thursday, April 23, 2004, I traveled to Ulman, Missouri, where I met up with Robert and Lisa Sparrow who were taking their crew and eight grey Percherons to Nashville, Tennessee, for just such an event. In Nashville, we met up with Brad and Clint Schreiber of Plainview, Minnesota, who had traveled 800 miles with their eight black Percheron geldings to serve as the opposition in the reenactment of the Magdeburg Hemispheres experiment.

Otto von Guericke first performed the hemispheres experiment back in 1654 in Magdeburg, Germany, to demonstrate his theories regarding the strength of air pressure and the existence of vacuum. The reenactment in Nashville was a sister city cooperative event sponsored by Nashville’s Adventure Science Center, Sudekum Planetarium and Magdeburg’s Otto von Guericke Society. This was the first time this reenactment had been performed in the United States.

Friday was to be the practice day for the event but the day didn’t start off very well. The horses were stabled at Warner Park, a beautiful 2,400 acre equestrian park on the outskirts of Nashville, complete with 18 miles of riding trails and a steeplechase course. There was a miscommunication regarding both the time of the practice and the directions to the event. The organizers had changed the time of the practice from 1:00 p.m. to 11:00 a.m. to accommodate the four television crews that were there to provide publicity for the event, but had forgotten to tell the horsemen of the change. When the mistake was discovered, there was much scrambling on the part of the Sparrow and Schreiber crews to get horses harnessed, loaded and to the event site. Then the directions to the event site were wrong...

About the time everything was getting back on track and teamsters were ready to hook the wheel teams to the hemispheres, a thunderstorm pushed into the area. The only shelter from the torrential rains was a covered picnic area where picnic tables were quickly moved from under the shelter. And then the horses, crews and media crowded together in an attempt to get some shelter from lightning, rain and wind, that for a short time, seemed to be coming from every direction.

By the time the weather had cleared enough to start hitching the horses; both the media and the German speaking interpreter had disappeared. Lack of media was not an issue for the horsemen, but the lack of an interpreter created some real issues as the four members of the German reenactment team tried to communicate with Robert Sparrow and Brad Schreiber on just how the horses were to be hitched. The Germans had brought their own doubletrees and swing poles (which resembled log chains with hooks on each end). But Sparrow and Schreiber had commandeered 16 sets of 40-Horse Hitch harness from Zearing, Iowa, and were unable to communicate to the Germans that their hardware wouldn’t work on the “40” harness. Tensions mounted. So much for the positive spirit of sister cities and cultural exchange.

They worked up to it, starting with demonstrations such as Schreiber’s wheel team winning this “tug off” against about 20 volunteers. The result would have been the same with an ever so much longer rope and more volunteers.

The American teamsters pushed ahead with their practice, hooking the first teams to the hemispheres. This might have been the most nerve-wracking moment of the weekend. Drivers commanded their teams forward and the chains attached to the hemispheres tightened lifting the huge metal sphere into the air. It hung there for a few moments until the teamsters whoa’d their horses, backed them up and set the hemispheres down. The first test had been passed.

Crews added another team, ran lines and again the hemispheres held. By the time lines were being run on the sixes, the interpreter had shown up again. The Germans had long since gotten past the hardware issue and now their only communication was regarding some tips on showmanship. After all, this was a reenactment and they had a performance to give. By the time the eights were driven the Germans were all smiles and by the end of the practice, the Germans were very impressed with the horsemanship exhibited by the Americans.

What the American teamsters found out later was that when they perform the reenactment in Germany, the Germans bring eight individual teams. Each teamster stands beside and drives his own team. Also, their regular harness is not set up to drive an eight-up and thus the need for additional hardware. The Germans were impressed with the fact that Robert and Brad each drove his respective eight-up hitch.

Later, back at the stables, the crews rehashed the drama of the day and wondered what the next day would bring. At least one major question had been answered at the practice: Guericke’s theory of the strength of air pressure had been proven. Sixteen draft horses failed to separate the hemispheres.

On Saturday, it was the German reenactment team’s turn to shine. They arrived at the event dressed in period costumes. The Otto von Guericke impersonator was driven onto the field in a horse-drawn carriage. The two American teams led their horses to opposite ends of the field where they stood facing each other across the field, ready to do battle. The hemispheres lie between them.

The Guericke impersonator described (via interpreter) to the audience his theory of air pressure and what he hoped to demonstrate with the experiment. Then he produced 5-1/2 inch diameter hemispheres and asked a few children from the audience to come forward and try to separate it. The children failed and so they added more children to the ropes and tried again. This time the children succeeded and, with a popping sound, the hemispheres separated.

Next, the Guericke impersonator asked Brad Schreiber to bring his wheel team forward. Then he asked for about a dozen adult volunteers from the audience to come forward while the German re-enactors attached a rope to the doubletrees on Brad’s team. The crowd was very eager to participate and close to 20 people ended up on the rope. Brad asked his team to “get up.” For a few moments it appeared as though the human team would win. But, then Brad used his “I mean business” voice and the human team ended up lying on their bellies on the soggy ground of the field.

Finally, it was time for the main event. Draft horses against air pressure. The wheel teams were hooked up to the 24-inch diameter, 250 lb. hemispheres. Of course, you already know from the practice what the outcome would be. Finally, the eights were hooked and, as 16 horses pulled against each other, the hemispheres held and again Guericke’s theory proved true. The audience was impressed; most of them believed the draft horses would be able to separate the hemispheres.

The first two teams are hooked as young Ross and John Sparrow gather up the lines. That accomplished, the two teams attempt to separate the hemispheres. They continue to add teams until they have sixteen big powerful drafters trying to disprove the Magdeburg theory.

The final dramatic moment occurred when the Guericke impersonator asked a 12-year-old girl to come on to the field. By simply opening a valve and relieving the pressure, she did what 16 Percheron draft horses were unable to achieve...the hemispheres fell apart.

After sixteen Percherons have failed to pull the two hemispheres apart, the Otto von Guericke impersonator calls on a 12-year-old girl to come forward. The young lady effortlessly does what 16 Percherons had failed to accomplish by opening a valve which relieves the pressure and the hemispheres fall apart. Whereupon von Guericke’s impersonator declares the experiment a success.

The Significance of Guericke

Otto von Guericke (1602-1686) of Magdeburg, Germany, devoted himself to scientific research. It was his interest in astronomical systems and study of the universe that led to his conclusion that space beyond the celestial bodies must be a vacuum. He further concluded that if outer space were a vacuum it must be possible to produce such a vacuum on earth, too. His concept of empty space was venomously contradicted by his peers but after many failed attempts, in 1650 he succeeded in proving the existence of a vacuum.

In the history of engineering science he is known as the founder of vacuum technology. Guericke’s first success in creating a vacuum was achieved by pumping water out of a glass container with the help of a fire engine adapted to the purpose. This led to the development of the vacuum air pump.

Success with the air pump created new challenges in developing containers that were air tight and wouldn’t implode when the air was evacuated. Eventually his local coppersmiths and brass foundrymen developed the spherical devices which could better resist the hard stresses imposed by Guericke’s experiments. This made possible the highly successful two hemispheres demonstration using 16 horses trying to pull the hemispheres apart. The experiment visibly demonstrated the enormous power of the air pressure which could not be surmounted by the strongest power man had at hand in those times: the horse.

When producing a vacuum, Guericke observed forces which he attributed to the properties of air; that air possesses weight which can be measured. Guericke could measure the pressure of the air layer weighingon everything on earth with his long water barometer. The load of the air column pressed on the surface of the water in the container and forced a water column to rise in an evacuated glass tube. He observed that changes in air pressure related to changes in weather conditions and used those observations to make weather forecasts.

Guericke also became known as the father of electrostatics. Guericke constructed the first electrical machine, described electrostatic repulsion and attraction, and discovered electrical conduction. In Germany, he is considered to be the founder of experimental physics.