Question

By whom and when was Large Samrat clock built?

Answer 1

Galileo invented the largest smart clock means it's just Idea at the time. in 1656 clocks and developed.

Answer 2

The Samrat Yantra or Samrat clock meaning, Supreme Instrument was made on the orders of Maharajah Sawai Jai Singh II in 1728 and is the biggest sundial in the world.

The Samrat Yantra clock was built in India. The clock is made of marble and stone, the sundial may not be built of the latest technology, although it is so accurate there is just a 2-second margin of error  between the day and night.