Mendeleev's predicted elements
Dmitri Mendeleev published a periodic table of the chemical elements in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest. When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that as-then-unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminium and eka-silicon with atomic masses 44, 68 and 72 respectively.
Jacques de Billy
In the field of astronomy, he published several astronomical tables. First published in Dijon by Pierre Palliot in 1656, Billy's tables of eclipses is called "Tabulae Lodoicaeae seu universa eclipseon doctrina tabulis, praeceptis ac demonstrationibus explicata. Adiectus est calculus, aliquot eclipseon solis & lunae, quae proxime per totam Europam videbuntur". The tables were calculated for the years 1656 to 1693. This work also contains solar and lunar tables based on the Paris meridian. It also includes a detailed examination of problems involved in astronomical calculations.