Periodic table
Russian chemistry professor Dmitri Mendeleev and German chemist Julius Lothar Meyer independently published their periodic tables in 1869 and 1870, respectively. Mendeleev's table was his first published version; that of Meyer was an expanded version of his (Meyer's) table of 1864. They both constructed their tables by listing the elements in rows or columns in order of atomic weight and starting a new row or column when the characteristics of the elements began to repeat.
Beda Venerabilis' Easter cycle
In the year 616 an anonymous scholar extended Dionysius Exiguus' Easter table to an Easter table covering the years 532 up to and including 721. Dionysius' table was published in 525 and only a century later accepted by the church of Rome, which from the third century up till then had given preference to go on using her own, relatively inadequate, Easter tables. From about the middle of the seventh century all controversy between Alexandria and Rome as to the correct date of Easter ceased, as both churches were now using identical tables.