| 摘要 |
A sundial comprises a body portion having a cylindrical wall. A gnomon is connected to the body portion to cast a shadow on the cylindrical wall. A pair of flexible sheets are alternately mountable on the cylindrical wall. Fasterners allow rotation of the sheets about the longitudinal axis of the cylindrical surface to correct for differences between local civil time and standard time of the time zone of observation. The time lines are configured in accordance with the equation of time. Each sheet contains time lines which designate the time occurring in either the fall or spring solstice.
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