Stokes mortar
Stokes mortar is a 81 mm mortar or artillery model.
Also recorded as 3-inch trench mortar; 3 inch mortar Stokes; 81 mm mortar Stokes.
Overview
1910s 81 mm trench mortar by Wilfred Stokes.
In detail
It is associated with United Kingdom of Great Britain and Ireland.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“Stokes mortar”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q1767309: Stokes mortar
Consult the source