AbstractJai Singh made a contribution to a whole range of science. He developed instruments for accurate observation, he constructed observatories and produced trigonometrical tables.It was under his patronage and guidance that Jaipur was built to demonstrate the benefits of the application of science to society.He was open minded and made contacts with other scientists from all over the world, encouraging some of them to work with him in Jaipur.Jai Singh firmly proves the falsity of the traditional European view of India as being scientifically dead during the mediaeval period.