[All found in here.]

Sound or acoustic mirrors were one of the first early warning detection systems invented to give advanced notice of an approaching enemy aircraft. These worked by focusing the sound from the plane’s engine so it could be heard before it was visible.
Sound mirrors worked using a curved surface to concentrate sound waves into a central point, which were picked up by a sound collector and later by microphones. An operator using a stethoscope would be stationed near the sound mirror, and would need specialist training in identifying different sounds. Distinguishing the complexity of sound was so difficult that the operators could only listen for around 40 minutes.

At right:
Baron Manfred Freiherr Von Richthofen sits in the cockpit of his Albatros fighter for a photograph with his squadron, Jagdstaffel III. Richthofen was credited with downing 80 Allied aircraft before being shot down over the Somme, Northern France, during what was known by pilots on both sides as ‘Bloody’ April, 1917. Manfred’s brother, Lothar, is seated at front (fur collar).
At left:
Album cover art from 1969, with silhouette of the 1937 Hindenburg disaster and a bit of proto-photoshopoopage.
[Found here, caption from here.]
Update: From the wikiness:

The Picasso of circus art.
Fred G. Johnson’s (1892 – 1990) banners were used to illustrate A Century of Progress for the 1933 Chicago World’s Fair His artwork also advertised the Ringling Brothers, Barnum & Bailey and Clyde Beatty circuses.
Hired by banner painter Harry Carlton Cummins to clean equipment and stick up banners, Cummins taught Johnson how to paint them, which he did, producing as many as four a day. The art is fast, subjective and made to deadline.
Not to be confused with the great Fred Johnson, bass singer for The Marcels.

Todd Webb composed Sixth Avenue Between 43rd and 44th Streets, New York, 1948 from eight separate images. It depicts the west side of Sixth Avenue between West 43rd and 44th Streets, taken on the afternoon of March 24, 1948. Realizing he had to work fast to retain the same light, Webb plotted the shoot beforehand, lining up the edges of each photo with chalk marks on the sidewalk. The image was exhibited at the 1958 Brussels Worlds Fair, and he became internationally recognized as the “historian with a camera.”





What a treat for the earballs. Imagine what the people of 1948 considered oldies.
[Record store photo found here. Panorama (with caption) and others from here thanks to a Tineye search.]


London England: “A Victorian couple trying not to laugh while getting their portraits done, 1890s.”
[Image found here.]
[Images from Life Magazine (November 1948) found here. Related posts here.]