Bhopal (Madhya Pradesh): The modern world still marvels at a few traditional items. And Sunnapuganugu, a device for preparing binding mixtures, is one such piece.
This device used for construction work is on display at an online exhibition series-58 on social media pages of Indira Gandhi Rashtriya Manav Sangrahalaya (IGRMS), Bhopal.
The exhibit is kept in the Traditional Technology Park, an open air exhibition of the museum.
Sunnapuganugu is used to grind limestone and to prepare a lime binding mixture used for joining bricks and stone in construction work.
It is a circular stone track pit built by Khondalite stone pieces which is considered most suitable for this track pit with heavy weight resistance. This circular track is one-foot deep, one-foot wide and 11-foot width.
The main crushing roller Sunnapuraiis made of sand stone weighs around 350 to 400 km.
This roller has a square-shaped hole at the centre for fixing of wooden axle Polukarra.
The ingredients required to make this mixture are lime powder, sand, sugarcane jaggery, bael fruit (Aegle marmelos), tree silt, Aloe Vera (Aloe barbadensis miller), Harra (Terminelia chebula) etc.
The process of mixing the ingredients is completed in two stages. In the first stage, lime powder is prepared in the Sunnapubatti furnace for heating limestone.
In this furnace, limestone is heated with coal in the ratio of 1:3. Limestone is converted into powder by the energy of coal in the furnace.
Museum associate Pritam Choudhary says that in the second stage, lime powder and sand are mixed in the ratio of 1:3 by Sunnapuganugu and mixed with other essential ingredients like jaggery water, aloe Vera, fermented Harra and silt obtained from trees.
By pulling the wooden axle with the help of a bull or male buffalo, Sunnapurai is driven. The material gets crushed due to the weight of the wheel. Jaggery water and fermented Harra are added to the mixture after completion of every 10 rounds.
The structures made from this mixture remain cool during the summer. In the historical period this binding mixture has been used for constructing many forts, wells, step wells, bridges, memory pillars and religious places etc.
This traditional technique is still used in the renovation work of various archaeological heritage sites in India, Choudhary adds.
Visitors can see this exhibition on the official sites and Facebook pages including (https://igrms.com/wordpress/?page_id=4002) and (https://www.facebook.com/NationalMuseumMankind) of the museum in addition to Youtube link (https://youtu.be/YW5W1hT0Lh8).