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.
Rudolphine Tables
In 1551, following the publication of "De revolutionibus orbium coelestium" by Nicholas Copernicus, Erasmus Reinhold produced the "Prutenic Tables" based on a heliocentric model of the Solar System, but these were no more accurate than the earlier tables.