Encouraged by their success in arithmetic, they turned towards a higher branch of mathematics and gave to Europe the science of numbers and quantity, and named it algebra ("al'jabara," to bind parts together). Whether, as some claim, the Arab-Moors obtained their knowledge of algebra from their schools in Bagdad or Damascus, who, in their turn, had derived it from the Hindoos, or whether, as others claim, the Jews, in their diligent translations from the early Greek geometricians into Arabic, must have come across, and followed up the algebraic trace, which is supposed to exist in the treatise of Diaphantus (350 A. C.), or whether the Moorish claim be the true one, that the honor of having invented algebra belongs to one of their own mathematicians, who flourished about the middle of the ninth century, to Mohammed ben Musa, or Moses,[23] whoever the inventors be of this valuable branch of mathematics, unanimity of opinion prevails concerning one point, and that is, the Arab-Moors and Jews first introduced algebra into Europe. Still more Ibn Musa (or Ben Moses) developed it to the solution of quadratic equations, and Ibn Ibrahim (Ben Abraham) to the solution of cubic equations, Ibn Korrah (or Ben Korah) to the application of algebra to geometry, laying thus the foundation of analytical geometry. Geometry led them to trigonometry, which they elevated to a practical science by substituting sines for chords and by establishing formulas and tables of tangents and cotangents and secants and cosecants. From trigonometry Al Baghadadi advanced to land surveying, and wrote on it a treatise so excellent, that by some it has been declared to be a copy of Euclid's lost work on that subject. [23] A copy of this Arabic work is preserved in the Bodleian library at Oxford, bearing a date of transcription corresponding to the year 1342. The unbiased student, who searches diligently among the achievements of the Moors and Jews, will soon detect, not only a systematic contrivance on the part of the literature of Europe to put out of sight our obligations to them in science, but a bold effort, wherever a chance presents itself, to wrest their hard toil from them, and bestow it upon some one, who is not so unfortunate as to be Saracen or Jew. But "injustice founded on religious rancor and national conceit cannot be perpetuated forever." The real truth can not be much longer hidden, and if the chapters of this volume have no other effect than simply to do justice to the memory of those who have toiled and who have suffered, that we may enjoy, to-day, the blessings of our civilization, we shall regard our labors amply rewarded.