An investigation of ancient astronomy shows that a cubit was used not only as the metric of length (elbow to fingertip) but also as a metric of angle in the sky. That suggested a new interpretation that fits naturally: the brightest celestial object—the sun—moves eastward around the sky, relative to the stars, during the course of a year, by one cubit per day!
Johnson writes:
A hint toward an interpretation of the odd phrase in the Book of Abraham comes from an extended meaning of the word cubit. Although originally and widely employed as a measure of length (above), the use of the word was extended by ancient scholars to include a measure of angle, especially in the sky.
Johnson states “as far as this author is aware, no precise interpretation of the phrase [one day to a cubit] has been given.” Previous speculation about this phrase can be found in several sources, including the following: George Reynolds, “The Book of Abraham—Its Genuineness Established,” Millennial Star 41 (Mar. 17, 1879): 161-163; Melvin A. Cook and M. Garfield Cook, Science and Mormonism: Correlations, Conflicts and Conciliations (Salt Lake City: Deseret News Press, 1967); and Allen J. Fletcher, A Study Guide to the Facsimiles of the Book of Abraham (Springville, UT: CFI, 2006).
Johnson provides limited support for his thesis, citing two examples of the use of the term to include a measure of angle: one by Marco Polo (ca. AD 1300) and one found in a Mesopotamian text from 331 BC.
Errors in the article include the following:
223: “1000” should read “a thousand”
223: “the earth” should read “this earth”
223 n. 1: “and FARMS” should be deleted.
224: “Kirtland Egyptian Project” should probably read “Kirtland Egyptian Papers Project”
224 n. 5: full citation not provided.
225: “Since the word [cubit] is now obsolete, it is of interest only because of its use in the Bible and the Book of Abraham.” I'm not certain that this statement is strictly accurate. I would suggest that it's also of interest because of its use outside the Bible and the Book of Abraham.
226: “water to” should read “water for”
226: “is more” should read “is still more”
226: “the moon was” should appear in square brackets.
226: “six” should read “6”
226: “below” should appear in square brackets.
226: “the constellation name” should edited to read “the Latin constellation name”
226 n. 12: subtitle of Wrestling with Nature is missing.
229: comma missing following “Horsens”
229: Latham’s translation of Travels of Marco Polo is missing from the bibliography.
229: listing for Studies in Scripture volume is missing the publication year (1985).
229: two publication dates are provided for Nibley’s Abraham in Egypt.
229: Peterson is misspelled.
230: subtitle of Wrestling with Nature is missing.
230: middle initial missing in Michael H. Shank’s name.