Joyeux Noël! (professor, are you STILL dowsing?) - eviltoast

In fact, this dates from the 1947 magazine, i.e. how Tintin was being published at the time.

Haha, and here’s a fun, fan-redraw:
https://i.imgur.com/uRpRRac.jpg

Artist: In The Depths of Solitude, via Tumbler