File:Umpqua NF Using a Heliograph c1910.jpg
Original file (3,793 × 2,675 pixels, file size: 5.67 MB, MIME type: image/jpeg)
Captions
Captions
Summary
[edit]
| Description |
English: (Per "Forest Service" on Flickr) "Umpqua NF - Using a Heliograph c1910". The Umpqua National Forest is in Oregon, in the United States (https://en.wikipedia.org/wiki/Umpqua_National_Forest). A heliograph is an instrument for communicating by flashes of sunlight reflected from a mirror (https://en.wikipedia.org/wiki/Heliograph).
The heliograph in this photo is comprised of the equipment on the two tripods on the man's left. The tripod closest to the viewer holds two mirrors - this "duplex" configuration was used when the heliograph was between the sun and the target - the mirror facing the viewer reflected the sun back to the second mirror, which reflected it forward to the six-blade shutter mounted on the second tripod. The man's hand is on the lever that opened and closed the shutter to create flashes for signaling - Morse Code or the like. The double-tripod heliograph used by the US Forest Service was the US Signal Service heliograph, model of 1905. The US Forest Service used the heliograph from 1908 through the 1930s and later. Forest Service use of the heliograph is described in some detail on pp. 160-181 of: W. N. Millar (1920), Canadian Forestry Service. Methods of Communication Adapted to Forest Protection (https://books.google.com/books?id=CI5OAAAAMAAJ). The profile for "Forest Service" on Flickr lists:"The Pacific Northwest Region of the U.S. Forest Service". This photo is listed as by "Forest Service" at https://www.flickr.com/photos/135886671@N08/21851071990/ with a "(CC BY 2.0) " license. This version has not been modified from that posted by "Forest Service". |
| Date | |
| Source | https://www.flickr.com/photos/135886671@N08/21851071990/ |
| Author | Forest Service |
Licensing
[edit]
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
|
This image was originally posted to Flickr by Forest Service - Pacific Northwest at https://flickr.com/photos/135886671@N08/21851071990. It was reviewed on 2015-10-24 22:30:23 by FlickreviewR, who found it to be licensed under the terms of the cc-by-2.0, which is compatible with the Commons. It is, however, not the same license as specified on upload, which was the cc-by-2.0, and it is unknown whether that license ever was valid. |
| Annotations | This image is annotated: View the annotations at Commons |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 22:28, 24 October 2015 | | 3,793 × 2,675 (5.67 MB) | Macchess (talk | contribs) | {{Information |Description ={{en|1=(Per "Forest Service" on Flickr) "Umpqua NF - Using a Heliograph c1910". The Umpqua National Forest is in Oregon, in the United States (https://en.wikipedia.org/wiki/Umpqua_National_Forest). A heliograph is an inst... |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
