Machine summary:
The earliest Jewish book on chronology, according to Horovitz, was composed more than a century later than the earliest work of the Arabs on the subject.
Rules were laid down about the various particulars which must be put down on the colophon of the manuscripts, and details of the methods of copying them and of collating these copies with their origi• nals have been described in the works on llm-al Derayah, A large number of Arabic manuscripts on various subjects which are preserved in the various libraries in the different parts of the world, show that these rules were generally observed by the competent and scholarly copyists.
This interest in facts and the critical and careful method in collecting and preserving them shown by the Arabs in the field of theological and historical composition reflected itself in their study of the various branches of exact sciences also.
They at first, as is well known, got translated the foreign works on various exact sciences into Arabic and made a careful study of them, but very soon they established their own observatories and other institutions in which they made their own observations of natural phenomena and collected together the results of their own experiences in the fields of various sciences and in their light established new scientific principles which have been explained and appre• ciated by such modern competent scholars as have made a thorough critical study of the Arabian works on them.