Sundial : 無料・フリー素材/写真
Sundial / RBerteig
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Sundial in the National Museum, Athens.The plaque reads, in part:#3156. Sundial. MarbleFound in the Theatre of Dionysus, Athens. Sundials were instruments for measuring time during the day. The concave surface (part of a cone) of the dial is divided by 11 engraved lines into 12 sections that correspond with the hours of the day (from sunrise to sunset). The horizontal line at the bottom of the dial marked the summer solstice, the line halfway up the dial the equinoxes, and the line at the top of the slab probably the winter solstice. The square socket at the top of the clock held a metal rod-pointer that cast the sun's shadow on the dial. The position of the shadow varied with that of the sun and thus indicated the hour of the day.Probably Roman period. |
| 撮影日 | 2006-03-24 03:13:58 |
| 撮影者 | RBerteig |
| タグ | |
| 撮影地 | |
| カメラ | NIKON D70s , NIKON CORPORATION |
| 露出 | 0.002 sec (1/640) |
| 開放F値 | f/1.8 |
| 焦点距離 | 50 mm |