As I remember, ~S~, (and it is well over 50 years since I read it ! ) the children, the young Bastables, thought that the gentleman under consideration was what in those days would be called a "Red Indian" - a Native American.

Hence, the "Indian Uncle".


Turned out he had been in the Sub-Continent.

The gentleman, etc., might have been some relation of the childrens' father, Mr Bastable Senior ; and ended up having a "play supper" with the young 'uns.