The Indian civilization is one of the oldest in the world if not the oldest. In thousands of years of learning the academicians of this great civilization had created an expanse of knowledge which was incomparable to any other known to mankind.
Such was the extent of the Indian scientific and mathematical knowledge that precise calculations regarding stellar alignments which eluded modern civilizations for hundreds of years were precisely done in the Vedas and other precious Sanskrit texts of the pre-medieval era. With the coming of the Mughals newer techniques of Math and Science were incorporated into Indian astronomical tools make them even more powerful and far reaching in terms of applications.
The Jantar Mantar in Jaipur was built in the year 1738 under the auspices of Raja Sawai Jai Singh and later renovated by the British Engineer and amateur astronomer Major Arthur Garret. Jantar Mantar literally translates into the calculating device or instrument and has a collection of several marble and bronze instruments which have extraordinary capabilities to make astronomical measurements and calculations.
The most important use of the Jantar Mantar was chronology and accurate measurement of Time. The systems used at the Jantar Mantar are extremely nuanced and even though for the general audience it is difficult to understand the exact functioning it is possible to get a gist of the essential features if you are attentive.
My kids are extremely curious and have intent to learn things. This is one crucial thing in life which I have tried to teach them since they were very young. The incredible central sundial which is the biggest in the world is the most important instrument at the Jantar Mantar and predicts time to an incredible accuracy of 10th part of a second. Such time keeping was impossible during the time it was built.
Another very important instrument which captured our imaginations was the Kapala Yantraprakara. It has the ability to convert celestial measurements into different reference frames and coordinate systems which is a method excelled only in the late 19th century. The Disha Yantra and the Dakshin Bhitti Yantra are also incredible pieces which tell the position and direction of celestial bodies with accuracy.