previous next


2. Hence, wherever a sundial is to be constructed, we must take the equinoctial shadow of the place. If it is found to be, as in Rome, equal to eight ninths of the gnomon, let a line be drawn on a plane surface, and in the middle thereof erect a perpendicular, plumb to the line, which perpendicular is called the gnomon. Then,from the line in the plane, let the line of the gnomon be divided off by the compasses into nine parts, and take the point designating the ninth part as a centre, to be marked by the letter A. Then, opening the compasses from that centre to the line in the plane at the point B, describe a circle. This circle is called the meridian.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License.

An XML version of this text is available for download, with the additional restriction that you offer Perseus any modifications you make. Perseus provides credit for all accepted changes, storing new additions in a versioning system.

load focus Latin (F. Krohn, 1912)
hide Places (automatically extracted)

View a map of the most frequently mentioned places in this document.

Sort places alphabetically, as they appear on the page, by frequency
Click on a place to search for it in this document.
Rome (Italy) (1)

Download Pleiades ancient places geospacial dataset for this text.

hide References (2 total)
  • Cross-references in general dictionaries to this page (2):
hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: