Friez USMC Field Heliograph Shutter #236 - Five view collage : 無料・フリー素材/写真
Friez USMC Field Heliograph Shutter #236 - Five view collage / signal mirror
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | A heliograph is a device used to signal by flashes of mirror-reflected sunlight.This shutter is from a heliograph made for the United States Marine Corps (USMC) in the United States Army Signal Service style, initially standardized in 1888, and largely patterned after the Grugan heliograph. This style of shutter, however, was introduced in 1905 - the prior (1892) model shutter had two leaves, and the 1888 model only one.This is a collage showing the front and four edges of the shutter. While all were photographed against 10 line per inch grid paper, due to parallax, I would only use the grid to dimension the center view, and even that is approximate.The engraving on the top of the shutter reads: "FIELD HELIOGRAPH U.S. MARINE CORPS No. 236", and on the bottom front of the shutter frame, "Julien P. Friez & Sons" at left, and "Baltimore, Md. U.S.A." at right. I have seen USMC heliographs with serial numbers ranging from 30 to 710. For a closer look, go to the full resolution versionJulien P. Friez was primarily a manufacturer of meteorological equipment, but manufactured hundreds of heliographs in the late 1800s and early 1900s. See: J.P. Friez heliograph ad, 1893. Julien P. Friez had a factory in Baltimore called "Belfort Observatory", after his birthplace in France, which he established in 1896.For more modern photographs of American heliographs, see the set: Modern Photos of US Signal Service Heliographs, for historical photos, see the set: Historical Photos of United States Army Signal Service HeliographsThis example is from a private collection in Arizona. |
| 撮影日 | 2013-11-30 20:50:20 |
| 撮影者 | signal mirror |
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