Scientists should always check the reliability of their instruments. Examples of what happens from failure to check are well known. At one time several astronomers believed that they had found rings around some of the outer planets besides Saturn, but an optical defect in their telescopes was involved. Again, Huxley’s "Bathybius" arose from a flaw in techniques. Creationist scientists use Scripture as an instrument, so to speak. Scripture is taken to be reliable. If any error was found in Scripture, then some doubt could be cast on other parts. This would be especially true were errors to be found in the historical and chronological parts of Scripture. Such errors have been claimed, on the grounds that the chronology of Scripture disagrees with other chronologies, especially that of Egypt, which many claim has been determined by astronomical methods. It is shown here that there is abundant reason to believe that the Scriptural chronology is valid, and that chronologies which disagree are really based, not on astronomy, but on questionable assumptions.