Original Smith nipple shape?

[Kevin Tinny]

Hello:

Noticed that the bottoms of both original iron and repro b-copper Smith nipples are domed, not flat.

Would appreciate anyone helping with why this shape was used, please? Thanks.

Kevin Tinny

[John Holland]

They are slightly convex shaped to fit flush at the bottom of the nipple seat, which is alternatively slightly concave shaped.

[Kevin Tinny]

Great and thanks, John.
Regards,
Kevin