ABSTRACT
The Arabs excelled in methodical accuracy. People owe them an immense debt for the introduction of the decimal notation, instead of the cumbersome numerical systems of Greeks and Romans, though even this system they adopted from India. Like other Oriental nations they failed in direction of speculative philosophy, and devoted their analysis rather to astrology than to astronomy. In 15th century Ulugh Begh, a Tartar prince, grandson of Tamerlane, was not only a patron of astronomy, but a practical astronomer. At the beginning of the 11th century, Ibn Junis produced a record of Arabian observations extending over nearly two centuries, including three eclipse observations, two solar and one lunar, made by himself near Cairo in 977, 978, and 979, by which the secular acceleration of mean motion of the moon was established. The Arabs for many centuries kept flame of astronomy alive, and by steady improvement in accurate observations, increased the value of each successive set of tables and constants.
