knob and tube : 無料・フリー素材/写真
knob and tube / jasonwoodhead23
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | knob and tube wiring this was an early standarized method of electrical wiring in buildings, in common use in north america from about 188- to the 1930s. it consisted of single-insulated copper conductors run within wall or ceiling cavities, passing though joist and stud drill-holes via protective porcelain insulating tubes, and supported along their length on nailed-down porcelain knob insulators. |
| 撮影日 | 2012-08-23 06:09:36 |
| 撮影者 | jasonwoodhead23 |
| タグ | |
| 撮影地 | |
| カメラ | TG-810 , OLYMPUS IMAGING CORP. |
| 露出 | 0.033 sec (1/30) |
| 開放F値 | f/3.9 |
| 焦点距離 | 5 mm |