JF Ptak Science Books Quick Post 
This is an interesting image without a story, though its implications are huge and the engineering involved is incredibly substantial. It appears in the September 1930 issue of Popular Mechanics, and shows a “huge concrete tube” connecting Africa and Gibraltar. the interesting part, the “strange” part of the title of the illustration), is that the tunnel is basically like an underwater bridge. When the idea of the tunnel was first proposed by the Spanish government in 1930 it was found that the rock between the two continents (and actually about where the two continents meet) was extraordinarily hard–too hard for the contemporary technology to deal with. One proposal to get around the tunneling aspect was to lay the tunnel above the bottom of the channel, which is what we’re looking at in this image.
