Alhazin, who wrote about A. D. 1080, made the great discovery of atmospheric refraction—that a ray of light when it touches the atmosphere is bent from a straight line; and consequently we see the sun before it rises and after it sets, in the same manner that an object lying at the bottom of a bucket filled with water appears in quite a different position from that in which it really is. He was the first to give that beautiful and scientific explanation of twilight, viz., the refraction of light, which is still regarded by modern scientists as the true one. He even attempted to ascertain the height of the atmosphere, which he estimated to be about fifty-eight and a half miles. This philosopher also wrote a treatise on weights and measures, and introduced that excellent system of weighing by means of a small, movable weight attached to the longer arm of a lever, as in our modern scales or steelyards. The Arabian astronomer, Ebn-Junis, was the first who made use of the pendulum in the machinery of clocks for the accurate measurement of the hours.
In the golden age of the Saracen empire, there were colleges in every part of its vast dominions. So numerous were these institutions, that more than six thousand students received instructions in them annually. In the far east were the college and astronomical observatory of Samercand; while in the western province of Andalusia were the famous school and observatory of Giralda.
The first medical college established in Europe was that founded by the Saracens at Salerno, in Italy; the first famous school of mathematics and astronomy was that established by them at Seville, in Spain.
Among them, learning was not confined to the rich, but every class received its benefits. The teachers of their colleges were paid liberal salaries for their services, and an allowance was made for indigent scholars, so that the son of the mechanic could graduate from the same class as the heirs of the Caliphs.
At first glance it seems remarkable that the wild ferocity of the Arabs should so suddenly change into a passion for intellectual pursuits; yet it should not be forgotten that this ferocity was to a great extent caused by religious enthusiasm. Thus, when the General Akbah had conquered his way from Egypt to the Atlantic ocean, opposite the Canary Islands, he rode his horse into the sea and drew his sword, exclaiming, "Great Allah! if my course were not stopped by this sea, I would still go on to the unknown regions of the West, preaching the unity of thy holy name, and putting to the sword the rebellious nations who worship any other gods than thee."
Again, when we consider that a large majority of their teachers and philosophers were of the Jewish nation, we see a beautiful Providence in all this. The remnants of God's chosen people, though exiles and wanderers, despised and down-trodden by the Gentiles, were yet the instruments in God's hands for the execution of His purposes and the elevation of the race.
Surely there is a broader, higher, grander meaning in the promise given to Abraham, "In thy seed shall all the nations of the earth be blessed," than many are willing to admit! And this is all the more remarkable, that, at the very time when mankind so much needed instruction, should occur what Milman so aptly terms, "The golden age of Judaism." Not an age of royal pomp and political power—that passed away with David and Solomon—but an age of intellectual culture, scientific research and practical discovery.
Strange it would appear to the casual student, if upon further research he should find that all great religious teachers have been of Israelitish origin, as well as a large proportion of those who have achieved distinction in the arts and sciences. But it was in Spain, southern France and Sicily that the Saracens attained their greatest power and influence; for there they came in contact with the nations of western Europe, and so influenced European manners, customs and modes of thought that through them that influence has been transmitted to our times.
To the ingenuity of the Saracens we are indebted for the origin of many articles of clothing and personal comfort. Their religion taught them to be clean in person. They did not therefore clothe themselves, according to prevailing customs in that age, in an under-garment made from the skins of wild beasts—a garment which remained unwashed and unchanged until it dropped to pieces of itself, a loathsome mass of vermin, stench and rags. They taught us the use of that often-changed and often-washed garment commonly called a shirt, which still is known among the ladies under its old Arabic name, chemise.
To them we are indebted for some of our most valuable fruits, such as the apricot and peach.