Researchers find ticking Tipu-era sundials engaging

Bengaluru: In an era of wearables and smart watches, two sundials—time-keeping machines— installed by erstwhile Mysore ruler Tipu Sultan continue to enthral tourists and researchers even today at Srirangaptna in Mandya district.

A team of astrophysicists from Jaipur recently came out with a research paper on the status and effectiveness of the instruments.

The researchers described the two sundials situated in Srirangapatna, one at Hyder Ali’s tomb (popularly known as Gumbaz) and another inside Jamia Masjid, as different from most known sundials in design and concept. They said the sundials were originally designed to tell prayer times in mosques in the absence of a mechanical watch.

These sundials engraved on granite slabs, which are currently maintained by the Archaeological Survey of India, show little wear and tear even though they have braved the sun, rain and the wind for a couple of centuries.

As part of the research, the study team computed the shadow lengths at Srirangapatna for various hours from the ephemeris data (calculated positions of the sun) and plotted the same on a simulated dial for the same day. Evidently, the plotted data and the observations were in agreement. The plot of the computer-generated data for the same date matches the observations on the sundials.

Using the exercise, researchers have analysed how people used to make use of the sundials for prayer timings daily. However, the numbers are barely readable now, said researchers.

Change in landscape blocks sunlight

Landscape changes have restricted the use of sundials in the present era. Tall trees to the east of Jamia Masjid cause long shadows in the morning.

These days, the sundial is usable from 10.30am to 2pm. After that, the sun hides behind the structure of the mosque in the west. It is learnt that the mosque did not have the first floor during 1782–1796 AD, and the dial could be used till late afternoon back then.

Similarly, for the sundial at Hyder Ali’s tomb, Gumbaz, one of the minarets erected later in the neighbourhood blocks sunlight on the dial for a significant duration of the day, the researchers added.

The research was done by Aalok Pandya from department of physics, JECRC University, Tej Bahadur from Manipal University and Sandip Bhattacharya from BM Birla Planetarium (all three institutions are in Jaipur) and is published in the recent edition of Current Science. Aalok Pandya is also part of Astronomy and Astrophysics Resource Development and Research Academy, Jaipur.

Sundials in India could be found in places like Delhi (Jama Masjid and Fatehpuri Masjid), Hyderabad, Pulicat in Tamil Nadu, Ghazipur and Nauli in Uttar Pradesh.

Tipu’s French clock made sundials redundant

As the construction of Jamia Masjid itself was completed around 1787 AD, it can be concluded that the sundial, which is ensconced on the top of a small platform on the first floor of the mosque, belongs to that era. The records further show the said installations became redundant soon after Tipu Sultan acquired a modern clock from France.

Researchers from Jaipur have observed that the sundial on the Jamia Masjid’s terrace has engravings on a near circular slab, whereas the one near Hyder Ali’s tomb Gumbaz is engraved on a square slab. There are eight equally spaced radial lines that intersect at the centre on the dials.