Bretzel liquide

This is from the Snow Motor sales film, it was a conversion kit that you could put on your tractor (or car!) during the winter. They show it pulling huge loads, and, on dirt it plows as it goes! Works on any surface but pavement.
tags: 1944, invention du premier suppositoire à vis tout terrain autotracté
http://fulgerica.com/en/2007/07/04/in-soviet-russia-cars-screw-you/
http://www.johnnypayphone.net/blog.php