Workers sawing timber underground in a mine as part of war work during WWI. The noise produced by the operation of tools on timbers is deliberately exaggerated to mask other sounds that could reveal valuable information to the enemy. This tactic makes it difficult to determine the direction of the sounds. The sound of the saw is equally audible whether it cuts wood or coal, but it appears louder at closer distances when cutting wood. The distance between the operator and the observer in this photo is 225 feet.

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Size: 8448px × 5862px
Photo credit: © piemags/NSC / Alamy / Afripics
License: Licensed
Model Released: No

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