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.
Toledan Tables
The Tables of Toledo were partly based on the work of al-Zarqali (known to the West as Arzachel), an Arab mathematician, astronomer, astronomy instrument-maker, and astrologer, who lived in Toledo. The tables were produced by a team whose membership is largely unknown, with the exception of al-Zarqali. Toledo came under Christian Spanish rule in the mid-1080s, shortly after the tables were completed. A century later at Toledo, the Arabic-to-Latin translator Gerard of Cremona (1114–1187) translated for Latin readers the "Tables of Toledo", the most accurate compilation in Europe at the time. During the mid-thirteenth century, Campanus of Novara constructed tables for the meridian of Novara from the Toledan tables of al-Zarqali.