 Born in Namur, Belgium in 1644, Thomas joined the Society of Jesus (the Jesuits) in 1660 and first taught in the schools of Armentières, Huy and Tournai.Equipped with a thorough training in Mathematics and Astronomy he was sent, at his own request, as missionary to China (1677).After a long and difficult sea journey - passing through Goa, Siam (Thailand), and Malacca - he reached Macau in 1682 just in time to observe an eclipse of the Sun (1683).