Staying alive in the trenches. While helping the "other guy" fail in that activity. This was the source of much ingenuity, such as these Aussies in an outpost in the trenches at Gallipoli.
The Digger on the right is using a periscope to spot for the Digger standing on the left who is using a trench mount to remotely aim and fire his rifle.
The other two are killing time, thinking of home and wishing they were elsewhere - but they're ready... three bayonets-mounted rifles lean against the trench wall in the center.
The Castle Armory counts in its holdings a slightly more polished version of that trench mount. While my personal opinion is that this is probably a reproduction that includes original parts, construction of these mounts varied widely, and it's possible that this is a true original. But the Castle Exchequer *paid* as if it was a repro, and it is represented here as such.
Simple enough - strap your rifle into the frame, insert the periscope, load and cock the rifle, slide up over the parapet... and then fiddle the 'scope until you can properly see the sights. Wedge the scope to hold the sight picture... and start looking for targets.
Downside is that you do have to pull it down or crawl up a bit to reload, which means you usually have to refiddle the periscope.
I've not had a chance to shoot it in this configuration, not yet having found or built a suitable place where I feel I could conduct that experiment safely, without danger of a shot going high and off-property. I have had a chance to get exasperated by the periscope, however!
For those of an interest - a larger format version of the SMLE Trench Mount can be had by clicking here.
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