Smith's Bible Dictionary

Dial "An instrument for showing the time of day from the shadow of a style or gnomon on a graduated arc or surface; "rendered" steps" in Authorized Version, (Exodus 20:26; 2 Kings 10:19) and "degrees," (2 Kings 20:9; 2 Kings 20:10; 2 Kings 20:11; Isaiah 38:8) where to give a consistent rendering we should read with the margin the "degrees" rather than the "dial" of Ahaz. It is probable that the dial of Ahaz was really a series of steps or stairs, and that the shadow (Perhaps of some column or obelisk on the top) fell on a greater or smaller number of them according as the sun was low or high. The terrace of a palace might easily be thus ornamented.