That's the Boer "Pom Pom " that Kipling talks about in the Boer war.
Reading those old books about the Boer war, India, and the Sudan I often run across references to "pom pom's", or Maxim Nordenfeldt's,or "Maxim 1pounders".
But I never saw a picture that gave decent perspective of the size of them.
Gives a WHOLE new meaning to,
Whatever happens, we have got
The Maxim gun, and they have not.”