The Tibetan tradition of rolling a wheel to obtain the effects of the mantra enciphered on it is curious — a mechanical action is interpreted in religious terms. Through the action of rolling, the mantra is executed or sent heavenward, in a gesture of “mechanised piety”. It is also claimed as a tantric technique to visualise the rotation of sacred syllables, like acoustic planets, around the nadi (human spine).

Historian of medieval technology Lynn White Jr writes that “the Tibetan wind-driven prayer-cylinder, constructed like an anemometer and rotating on a vertical axis is... perhaps the inspiration of windmills in general”. Although he cautions that the invention goes back to revolving bookcases in Chinese Buddhist monasteries — “usually octagonal” — that helped in referencing the Tripitaka (Buddhist scriptures).

The “conscious and generalised lust” for channelling nature’s own power for human ends would not be limited to mechanical devices but spread to every sphere of activity. The concept of crop rotation is a similar idea extended in time and space. Here the four seasons might as well stand for the phases of an engine (intake, compression, combustion and exhaust) which optimise the chemical content of the soil.

Merely harnessing the latent power of natural forces wasn’t enough; since antiquity, men of a certain intellectual bent have dreamt of perpetual motion machines — limitless power, which would make them masters of nature. The genesis of this concept seems to have been in India, with Siddhanta Siromani (AD 1150), where the mathematician Bhaskara II describes a hollowed wheel with rods, which when half-filled with mercury “will then revolve of itself”. From here the idea would percolate through the Islamic world to Europe — “just as it was transmitting Hindu numerals and positional reckoning at the same moment: Leonardo of Pisa’s Liber Abaci appeared in 1202”. Thrown into the scientific revolution that was soon to come, it would eventually result in the laws of thermodynamics (which prohibit any kind of perpetual device).

“In India the idea of perpetual motion was entirely consistent with and perhaps rooted in the Hindu concept of cyclical and self-perpetuating nature of all things [...] To Hindus the universe itself was a perpetual motion machine....” notes White Jr (in Medieval Technology And Social Change ). And because there was a significant delay in the arrival of European science to India in the 17-18th centuries the idea of perpetual motion remained extant.

There is a letter by Andreas Strobl, one of the Jesuit mathematicians in the employ of Sawai Jai Singh II, the astronomer-king of Jaipur. He writes that (prior to his death in 1743) Jai Singh “had worked on a perpetual motion machine, and had spent a sizeable sum equal to 50,000 guilders, on it”.

Meanwhile, European science was already past replacing the ancient geocentric view of Ptolemy with Earth as the centre of a moving universe — to the Earth as a rotating sphere. In De revolutionibus orbium coelestium (1543), Copernicus first attempts to seal the question of Earth’s shape, before going on to say how it could rotate: “Indeed, geometrical reasoning about the location of America compels us to believe that it is diametrically opposite the Ganges district of India.” His curious reference to India may have emerged from the Waldseemüller map of 1507, which identifies this Ganges.

Within India itself there were lingering doubts related to the old system, too feeble and scant perhaps, but notably voiced by Mulla Mahmud Jaunpuri (1606-51) in his work Shams-e-Bazighi during the reign of Shah Jahan.

Jai Singh II’s encounter with the telescope was not entirely without consequences too, even though the full implications of the Copernican revolution had been prevented from reaching him. His assistant Mirza Khairullah Muhandis cast doubt on the Ptolemaic circles and started talking of ellipses. According to scholar SA Khan Ghori, the king himself had begun verifying the discoveries made by Galileo — such as the phases of Mercury and Venus, the shape of Saturn, the satellites of Jupiter, worlds rotating around worlds. He began to question the basis of the Ptolemaic thought that the distant stars were fixed and unmoving. Jai Singh II writes in the khatima of his royal almanac Zij-i-Muhammad Shahi: “Those stars that are termed “fixed stars” in the terminology of astronomers are not fixed and stationary in reality. Nor do they move with one rate of velocity, but with different velocities.”

For that brief moment, his mythical perpetual machine — that eternal dervish in the deep — was not the universe he was looking at every night, but the very ground he was standing on. The axle of this geological motor was the invisible line that extended the hypotenuse of Samrat Yantra (the largest sundial in the Jantar Mantar observatory) to Dhruva (the Pole Star). The king became trapped inside an Earth-sized Tibetan prayer wheel, tilted at 27 degrees, whose sanctum concealed the mantra to be sent heavenward.

Rohit Gupta explores the history of science as Compasswallah; @fadesingh