(Vitruvius names Cicero and Lucretius as post nostram memoriam nascentes.) The subjects of the eight chapters are - (1) the signs of the zodiac and the seven planets; (2) the phases of the moon; (3) the passage of the sun through the zodiac; (4) and (5) various constellations; (6) the relation of astrological influences to nature; (7) the mathematical divisions of the gnomon; (8) various kinds of sundials and their inventors.
He taught, if he did not discover, the obliquity of the ecliptic, is said to have introduced into Greece the gnomon (for determining the solstices) and the sundial, and to have invented some kind of geographical map. But his reputation is due mainly to his work on nature, few words of which remain.
His Lectiones in omnes Psalmos Davidis (1635) is exceedingly suggestive and terse in its style, reminding of Bengel's Gnomon, as does also his Commentarius utriusque Epist.
More surprising as the Chinese astronomers are credited with having made use of the gnomon as early as 1000 B.C. for determining latitudes.
Wood, Cryptopora gnomon Jeff., Rhynchonella (Hemithyris) psittacea Gmel., Crania anomala Mull., and Discinisca atlantica King.
The works on which Bengel's reputation rests as a Biblical scholar and critic are his edition of the Greek New Testament, and his Gnomon or Exegetical Commentary on the same.
He modestly entitled his work a Gnomon or index, his object being rather to guide the reader to ascertain the meaning for himself, than to save him from the trouble of personal investigation.
Bengel's hope that the Gnomon would help to rekindle a fresh interest in the study of the New Testament was fully realized.