Round and square cantles

[Clava]

What is the difference in the shape of the tree in relation to the shape of the cantle? (pony saddles in particular). A saddler has suggested that my pony which is on loan requires a square cantle and not a round one, and it made me wonder what the differences are? Many thanks.

 

[Orchardbeck]

I think square cantles are mostly seen on wider treed saddles such as cob and wide pony saddles - I know this is the case on the Thorowgood/Kent and Masters ones anyway. The narrower ones have round cantles.

I'm not sure if there is a design reason for this though, or whether it is just to indicate the different types.

 

[Clava]

Thanks, I've since spoken to my saddler who says the trees are the same (which is what I thought), but a square cantle can allow for a bigger bottom.