Mathematical Treasure: Oughtred's Clarification of Euclid

William Oughtred’s Elementi decimi Euclidis Declaratio [Euclid’s Ten Elements Clarified] (1662) was one of many books at this time that attempted to explain or make simpler Euclid’s Elements. It is interesting that the author identifies himself merely as “Anglo” or English.

Here on the first page of the text, Oughtred, who is noted for his pioneering employ of symbolism, provided a table of the symbols he used. The tabulation begins with “equals” and “similar” and then advances to more intricate relationships such as “Majus” (greater than) and “Aequale vel majus” (equal or greater than). The other symbols are worthy of inspection.

The images above are provided courtesy of Archives and Special Collections, Dickinson College, Carlisle, Pennsylvania.

Index to Mathematical Treasures