In the heyday of its expansion across the Indian subcontinent, the East India Company soon discovered that classical intelligence networks in Asia were a gossamer, puzzling web. The spies could be fakirs, servants, wealthy merchants, darbari news writers, postmasters, soothsayer saints, princes or even wandering monks — just about anybody. Illiterate tribals were useful as couriers, for example — since they couldn’t read the messages.

In his pioneering study of information networks in India before and during the Raj, the (recently deceased) historian Sir Christopher Bayly added that, “The news writers, and in particular the burains — old ladies — employed by them as peeping-toms in the women’s headquarters, kept all India amused for years with a flow of dirty stories until a more severe morality intervened in the 1830s.” The news writers (akhbarnavis) in every court were not ambassadors or foreign correspondents, but a mutually tolerated system of espionage. Their presence signified trust among the rulers, an interest in each others’ policies, and an expulsion was tantamount to a declaration of war.

In order to control India, the British had to understand it. The plethora of Indic dialects and scripts posed a great difficulty — and this naturally turned their attention towards its languages and history, marking the birth of Orientalist studies. In 1786, the philologist William Jones declaimed, “The Sanscrit language, whatever be its antiquity, is of a wonderful structure; more perfect than the Greek, more copious than the Latin, and more exquisitely refined than either, yet bearing to both of them a stronger affinity, both in the roots of verbs and the forms of grammar, than could possibly have been produced by accident…”, suggesting a common origin of Indo-European languages. Soon after this in the 1830s, the scholar James Prinsep deciphered the mysterious stone inscriptions strewn across the subcontinent — declaring them to be the edicts of Emperor Asoka, written in the Brahmi script.

Meanwhile, ‘neutral’ and largely unexplored regions in the north such as Tibet and Afghanistan were being squeezed into a power struggle across Central Asia between the Russians, British and Chinese powers (even Germans). This long tussle for supremacy was coined The Great Game by a British officer in Uzbekistan, Captain Arthur Conolly — before he was beheaded by the Emir in 1842 for spying as one ‘Khan Ali’.

One of the better known passages happened when the East India Company attempted to survey the forbidden kingdom of Tibet. Entry was banned to foreigners, being punishable by death. A group of intrepid Hindu pundits were trained by a British colonel — Thomas Montgomerie, to penetrate the mystical ranges surrounding Lhasa. Not only did these ‘monks’ — Nain Singh Rawat and his brothers — have to travel without blowing their cover, they had to map the areas accurately using instruments of surveying, triangulation, and astronomy.

To this dangerous end, the pundits were trained to walk 33 inches a pace, making 2,000 paces in each mile. Instead of the usual 108, a special rosary of 100 beads would keep the count. Secret compartments concealed a compass and sextant to observe the position of stars, begging bowls had a hidden mercury level to find the horizon, thermometers to measure the altitude from the boiling point of water, and a Tibetan prayer wheel concealed their scribbles. Perhaps at times they would have memorised their observations as mantras, for fear of being seen with paper and pencil. Other secret techniques (talismanic locks, poisonous seals, invisible inks!) may have been involved in these battles of subterfuge. Our evidence is scant, but we can make some educated guesses.

Two main encoding schemes for written language have been observed in Indian manuscripts since ancient times. The first is the Katapayadi system used largely in Kerala, in which syllables stand in place for numerals. The second is the Bhuta Samkhya cipher in which certain words or phrases denote numbers. For example, in the latter — eyes would denote the number two, and teeth would equal 32. An arrow would mean five, because the Hindu deity of love — Kamadeva, is depicted carrying five flowery arrows. These words could be strung together in verse using the ‘place value system’ to depict larger numbers by both astronomers or spies. Sanskrit poetry is known to contain highly mathematical structures such as palindromes and error-correcting codes, as seen in the epic poem Shishupala Vadha by the 7-8th century poet Magha.

Moreover, whispering galleries are found in many fortifications and palaces — Gol Gumbaz (Bijapur), Victoria Memorial (Calcutta) and the Bankipore granary to name a few. They embody the geometrical properties of an ellipse (or oval), which is also the shape of planetary orbits. As a circle has one centre, an ellipse has two focii. Anything spoken at one focus will reflect from its periphery and can only be heard at the other focus. Elliptical arcs across hilltops and courtyards can thus be used to communicate in secrecy with friends, if one prefers to keep one’s enemies closer.

( Rohit Gupta explores the history of science as Compasswallah)

Follow Rohit on Twitter @fadesingh