<p>made during a summer day in Warsaw's Museum of the Polish Army;
</p>
French WWI Dumesille system <a href="https://en.wikipedia.org/wiki/Mortier_de_58_mm_type_2" class="extiw" title="en:Mortier de 58 mm type 2">58 mm trench mortar</a>, used by the Polish Army in the Polish-Bolshevik War
Halibutt
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>