The correspondence between Leibniz and Teuber continued. From Hanover, on 3rd July 1716, Leibniz wrote a letter to Teuber informing him of his visit to Zeitz to clear up the remaining problems connected with his calculator, which was a marvelous invention of the time. His calculator performed flawlessly doing all sorts of mathematical operation. - Addition, subtraction, multiplication, and division. Moreover, his calculator could also extract a root. He told Teuber in the letter that he was going to visit Duke Moritz Wilhelm. According to the court diary, Leibniz arrived on 10th July 1716 and Duke Moritz Wilhelm treated him as the guest of honour. Leibniz spent a week there, amending his calculator, which had been designed there, and on his way back paid a brief visit to Orffyreus again.

During the same period, Count Karl Landgrave of the Hesse- Cassel [i], much interested in science of mechanics, came to know about Orffyreus and his wonderful wheel. Leibnitz also recommended Bessler to Count Karl for the sponsorship of his invention. Count Karl was a rich and royal elite so was able to help Orffyreus’ work substantially. At this time, Count Karl, was 62 years old and was living at Weissenstein Castle at Hesse-Kassel. Though Count Karl ruled over one of the tiny quasi-independent states which were numerous in that of Germany’s development, leading powers in northern Europe well recognized him as a stead fast ally in the many wars which took place at his time.  He had personal and political association with the kings of England, Poland, Prussia, and Sweden He negotiated at high levels on several political issues.  He was a successful ruler.  Conditions of the Hesse-Cassel were poor before he came to power.  His small country became well-off due to his mercenary army which could be hired from him by other states at war - at a considerable price, of course. In England it was the trading of slaves and other colonial produce that proved to be the most profitable of businesses. Count Karl gained his money and respect by equipping and hiring mercenaries.

Count Karl had spent nearly all his life with warfare but in the latter part of his life he turned to the arts and sciences. He understood importance of science and technology to develop industry.  He worked hard, encouraged scientist, patronized them, engaged them in many large building projects which were successful and contributed a lot to the development of the state and as a result, when he had died, he left Hesse -Cassel in an excellent financial position.

Count Karl was very popular for his collection of the latest scientific instruments.  Among these were various unusual clocks based on rolling ball mechanism, erroneously called as perpetual mobile.  He purchased one such perpetual mobile from Cassipani, inventors of several unusual clocks during his visit to Italy between December 1699 and April 1700. We can therefore see that the Landgrave had a technical vein. He exhibited numerous machines, devices and other things of technical interest.  Many eminent scientists living in his time acknowledged his merit.  Gottfried Leibniz and Christian Wolf were among his admirers.

The monarch took an interest in technology throughout his life, in so much as he, a devoted Protestant, had invited Huguenots who were exiled from France to his own country. Among those arriving at court was Denis Papin, who had achieved great merits in the development of the steam engine. The Count Karl patronized Denis Papin, inventor of steam engine.  . Papin had moved to Kassel in 1695, where he carried out a series of famous experiments with the help and support of the Landgrave. He became Professor of Mathematics at the University of Marburg, and remained in the Landgrave’s services for 20 years. Papin had been a collaborator with Huygens in Paris and Boyle in London. He invented the safety valve and an early form of pressure cooker. Papin could not carry out his experiments with the steam engine in the court for very long because Desagulier soon claimed that he invented a better steam engine which really proved to be better than Papin’s. In his castle, Count Carl installed the first steam engine in mainland Europe. It had the simple task of raising water for the cascade at the front of his castle – much to the astonishment of the public. 

Count Karl Offers Orffyreus A Post of Councilor (1716)

 When Count Karl learnt about Orffyreus and his wheel performing mechanical wonders, never done before, he decided to see truth of his machine and support Orffyreus. Orffyreus was already struggling a lot in finding some support.   The inventor was fortunate in securing count Karl’s support. It is also reported by few authors that Count Karl also bailed him out and offered him lodging in his castle.  Karl possessed money as well as position or influence - poor Orffyreus had neither. In 1716, Prince Karl took Orffyreus under his patronage.  Cont Karl was kind enough to offer Orffyreus a post of councilor, which Orffyreus gladly accepted though his duties were of a kind ill suited to his aptitude for the perpetual motion. He then became Councilor Orffyreus. He seized on the opportunity that came to him from providence.  Karl provided him with the resources to build his largest wheel. This was a fortunate break for young Orffyreus.

Author of the book "Forbidden Inventors", George Egely writes:

 “New opportunities and new horizons opened up when Orffyreus was employed in the service of Karl the Landgrave of Hesse-Kassel, the richest and most distinguished Lord. …..This was the Golden Age for Orffyreus, up until the Karl’s death at the age of 76, in 1730. The Landgrave paid great attention to his country and its commerce. For this reason he set up a Commercial Chamber, where he offered a job to Orffyreus. Orffyreus became a Commercial Councillor with an annual payment of 300 Thalers, which was not a small sum at that time. He thus obtained work, payment and rank.”

Now Orffyreus had workshop, tools, and an influential sponsor.  It provided an atmosphere where his natural mechanical and scientific talents could flourish.  Orffyreus was a poor man of humble origin and surroundings. The obstacles confronting Orffyreus however, were nearly insurmountable because he was not formally educated and trained, he had no scientific status or prestige, and so his ideas faced constant ridicule 

Orffyreus' connections in scientific world were not strong. With help of Count Karl he raised his hopes to enter into scientific world to get some position on the strength of his mighty invention.  In the beginning, he was not able to decide whether he should sell his invention to any one or petition legislature of Hesse Castle for exclusive rights to use his perpetual motion machines in mining, pumping and carriages in those states.  The scheme of using steam engine to pump water to a main overhead reservoir to operate a water wheel was too cumbersome and inefficient. He wanted to replace it with his perpetual motion machine and surprise the world that his acumen was superior to Edward Somerset, Denis Papin and Desoglier- all who developed a steam engine to make a position in scientific world.  Perhaps Count Karl refused that part of petition concerning use of Orffyreus machine in carriages, on the ground that the idea was so preposterous that he was not able to waste his time giving it a serious consideration, although there was no theoretical basis with which to prove it. With help of Karl and Leibniz, Orffyreus then pursued other alternative to sell his invention.

Count Karl had a large family.  On 21 May, 1673, Karl married his first cousin Maria Amalia of Courland (1653–1711), daughter of Jacob Kettler, Duke of Courland. They had seventeen children, 12 sons and 5 daughters.

 After 38 years of marriage, his wife Maria Amalia died in 1711.   Karl’s 17 children married into a number of good courts: one of his sons, for instance, became King of Sweden. In his last years, the Landgrave could not enjoy peace as his two wives were always quarreling with each other. For this reason, Count Karl was not able to give proper attention to Orffyreus.  It adversely influenced Orffyreus’ fate.