This undated old postcard, presumably produced in Germany, illustrates the Devil's Bridge legend that is found in dozens of locations throughout Europe.
There are numerous variations to the legend, but it usually goes something like this: A village or individual is faced with a difficult engineering challenge in trying to construct a needed bridge. The Devil agrees to help, under the condition the he receive the soul of the first to pass across the bridge after its completion. The Devil is then outwitted when a goat (or, in the case of this postcard, a dog) is sent across the bridge first, infuriating Old Scratch.
This is the German text from the back of the postcard:1
"Die Sage berichtet, dass der Teufel mit dem Baumeister sich einigte, diesem beim Brückenbau zu helfen, unter der Bedingung, dass das erste über die Brücke gehende lebende Wesen dem Teufel gehöre . — Als die Brücke fertig war, trieb der Baumeister einen Hund über die Brücke und so wurde der Teufel überlistet."
In addition to the Devil's Bridge Wikipedia page, a good resource for this folklore topic is this webpage by retired professor D.L. Ashliman on the University of Pittsburgh website. Ashliman has collected more than a dozen versions of Devil's Bridge tales from Germany, Austria, Switzerland, Wales, and England. Here's a short one from Switzerland:
"A Swiss herdsman who often visited his girlfriend had either to make his way across the Reuss River with great difficulty or to take a long detour in order to see her.In other versions, the goat is not killed, but the angered devil rips off part of its tail and, thus, in addition to being a Devil's Bridge tale, it's a pourquoi story: "Why the goat has a short tail."
"It happened that once he was standing on a very high precipice when he spoke out angrily, 'I wish that the devil were here to make me a bridge to the other side!'
"In an instant the devil was standing beside him, and said, 'If you will promise me the first living thing that walks across it, I will build a bridge for you that you can use from now on to go across and back.' The herdsman agreed, and in a few moments the bridge was finished. However, the herdsman drove a chamois across the bridge ahead of himself, and he followed along behind.
"The deceived devil ripped the animal apart and threw the pieces from the precipice."
1. The only other text on the back of this split-back card, which was never mailed, states: "Gebr. von Matt, Altdorf."