The Sun-Dial of Ahaz

Calvin's Commentaries, Vol. 15: Isaiah, Part III, tr. by John King, [1847-50], at sacred-texts.com

THE SUN-DIAL OF AHAZ.

This is believed to be the earliest account of a Sun-Dial that is anywhere to be found in history, and, on that account, has arrested the attention of scholars little addicted to the study of the Holy Scriptures. The form of it, which can now be nothing else than a matter of ingenious conjecture, has been investigated with uncommon industry, and illustrated with great profusion of learning. Little aid can be obtained from the incidental notice of the sacred historian, which our author has expounded with more than his usual conciseness.

A preliminary question relates to the Hebrew word מעלות, (magnaloth,) which, like the Latin word gradus, literally means steps, but might naturally enough mean degrees. It has been contended that βαθμοὺς the term used by Josephus, is liable to a similar ambiguity, and may have been used by him in its literal signification. Michaelis differed so widely from this view, that he considered, מעלה (magnalah) to signify a degree, in the sense used by modern mathematicians, who divide a circle into 360 degrees, so that 10 degrees (10°) would denote the ninth part of a right angle; and he supports his opinion by shewing that this use of the word degree did not take its rise among European philosophers, but traveled from the East, and, like our ordinary numerals, had an Arabic origin.

Assuming that the word denotes steps, there is still abundant room for diversity of interpretation. Some have thought that there was a flight of steps leading to the royal palace of Ahaz, on the top of which was placed a gnomon, (or obelisk,) and that the steps served to measure the shadow of the sun which was thrown upon them. Others refer it to an earlier period, when the sun-dial consisted of a massive structure, towering into the sky like other monuments of Oriental architecture, and built with scientific precision, but unfitted by its cumbrous form to vie with the accuracy and elegance of lighter instruments which belong to a more advanced age of science The type of such buildings is naturally sought, not in Judea, where such studies were never cultivated, but among the Egyptians, and especially among the Babylonians, to whom the Greeks and other nations were indebted for their knowledge of astronomy. Πόλον μὲν γὰρ γνώμονα καὶ τὰ δυώδεκα μέρεα τὢς ἡμέρης, παρὰ Βαβυλωνίων ἔμαθον οἱ Ελληνες “For the Greeks learned from the Babylonians the dial, and the gnomon, and the division of the day into twelve (parts) hours.” (Herodotus Eut., 109.) Nothing is more natural than to suppose that Ahaz directed some architect to copy a celebrated building in Babylon, the general form of which may be gathered from the description given by Bishop Stock,* whose version of the passage, and note, accompanied by a drawing, we shall lay before our readers: —

Behold, I turn the shadow of the degrees,
By which the sun is gone down on the dial of Ahaz,**
Backward ten degrees.
So the sun turned back ten degrees,
On the dial, by which it had gone down.

In what manner the shadow was made to go backward ten degrees is a question totally distinct from the form of the dial. That it was effected by a motion of the sun itself, or by a change of the relative position of the earth to that luminary, though this has been boldly stated and argued, is a notion too extravagant to need refutation. There is plausibility in the view suggested by Doederlein, that “the change of the shadow depended entirely on a cloud, which intercepted, and in a manner altogether extraordinary refracted, the rays of the sun, and thus made the shadow or the light to go back ten degrees.” Rosenmuller relates, on the authority of another commentator, an alteration of the shadow of a sun-dial, to the extent of an hour and half, which was effected by the shadow of a cloud at Metz, in the beginning of the eighteenth century. Without inquiring into the historical evidence of such an occurrence, or entering into long and intricate reasonings on the principles of optics, which would be unsuitable to this place, we shall only remark, that the transaction was undoubtedly miraculous; for it is declared to have been “a sign from Jehovah.” In this respect, it is but one of innumerable miracles which were performed by an Almighty hand in the sight of the Jewish people, and which have been recorded in order to strengthen the faith, and aid the devotion, of the worshippers of God in all ages, who delight to “praise the Lord for his goodness, and for his wonderful works to the children of men.” — Ed.