An absolutely phenomenal airline route diagram from 1939, which is both map and schedule in one. 

The thicker route lines represent the routes that belong to Polish Airlines LOT – one of the oldest continually operating airlines in Europe; they still use the beautiful flying crane logo today – with thinner route lines representing partner or connecting airlines. Red lines show daily service, black lines show weekday or irregular service. The departure and arrival times for each flight are indicated within the circles at each city – for the most part, the bigger the circle, the more flights serve it, although Warsaw’s importance is overstated somewhat as LOT’s main hub. Red times show the different schedules for Sundays. The flight/route number for each flight is superimposed over each route line: you can see that some flights “hop” from city to city along the way.

Ominously, a legend at the bottom states: “The services on all lines passing through PRAHA (Prague) are suspended until a special notice is given.” Czechoslovakia had, by this time, been occupied by Nazi Germany, and WWII was about to break over Europe like a wave.

Our rating: Information-rich and weirdly beautiful in a very abstract way. I love this so much: five stars!

Source: histmag.org (in Polish)