how to make "jam tins."

Previously an order had been issued for all ranks to save empty jam
tins for the manufacture of bombs. A Professor of Bombing would sit on
the fire step in the front trench with the remainder of his section
crowding around to see him work.

On his left would be a pile of empty and rusty jam tins, while beside
him on the fire step would be a miscellaneous assortment of material
used in the manufacture of the "jam tins."

Tommy would stoop down, get an empty "jam tin," take a handful of
clayey mud from the parapet, and line the inside of the tin with this
substance. Then he would reach over, pick up his detonator and
explosive, and insert them in the tin, the fuse protruding. On the
fire step would be a pile of fragments of shell, shrapnel balls, bits
of iron, nails, etc.-anything that was hard enough to send over to
Fritz; he would scoop up a handful of this junk and put it in the
bomb. Perhaps one of the platoon would ask him what he did this for,
and he would explain that when the bomb exploded these bits would fly
about and kill or wound any German hit by same; the questioner would
immediately pull a button off his tunic and hand it to the bomb-maker
with, "Well, blime me, send this over as a souvenir," or another Tommy
would volunteer an old rusty and broken jackknife; both would be
accepted and inserted.

Then the Professor would take another handful of mud and fin the tin,
after which he would punch a hole in the lid of the tin and put it
over the top of the bomb, the fuse sticking out. Then perhaps he would
tightly wrap wire around the outside of the tin and the bomb was ready