: During the Middle Ages, the Moors in North Africa and Al-Andalus (Spain) preserved and advanced sciences, including geometry, architecture, and mysticism . This "Moorish Science" is often cited as a foundational influence on European builders and the eventual development of speculative Freemasonry .
More concretely, some Masonic research lodges publish “tract 19” or “monograph 19” in a series. The phrase “19 work” might indicate the 19th degree of a certain rite (though the Scottish Rite has 33 degrees; 19th is generally labeled “Grand Pontiff”).