New Delhi: The 18th-century astronomical marvel of Jantar Mantar in Delhi is set to shine once more as the Archaeological Survey of India (ASI) embarks on a meticulous restoration of two key instruments, the Dakshinottar Bhitti Yantra and the Karka Rashi Valaya of the Mishra Yantra. This initiative follows the successful completion of restoration work on the iconic sundial atop the Samrat Yantra.
According to ASI spokesperson TJ Alone, conservation efforts for both the Dakshinottar Bhitti and Karka Rashi Valaya Yantra are currently in progress. Detailed documentation and working drawings of the astronomical scales have been prepared, paving the way for marble slabs to be engraved at a specialised workshop. Once completed, these slabs will be installed at Jantar Mantar, followed by expert evaluations to ensure precision. The entire restoration process is anticipated to conclude within six months.
This initiative comes in response to a directive from the Delhi High Court, which mandated ASI to report on the condition of these instruments after a contempt plea highlighted previous inaction dating back to September 2010. In light of this, ASI formed a six-member committee last year to oversee the restoration.
The Dakshinottar Bhitti Yantra, known as the north-south wall instrument, holds the distinction of being the most compact device within this historical observatory. Situated on the eastern wall of the Mishra Yantra, it plays a crucial role in measuring the altitude at the meridian, facilitating the determination of the shortest and longest days of the year during the summer and winter solstices, which typically fall on June 21 and December 22, respectively.
On the other hand, the Karka Rashi Valaya, located on the rear wall of the Mishra Yantra, is primarily utilised during the summer solstice when the sun aligns with the Tropic of Cancer. At this time, sunlight strikes the instrument at a grazing angle, allowing for shadow observations to commence about two months before June 21. However, these observations can only be recorded for a limited duration due to weather conditions, particularly during the monsoon.