The IGI has an extracted marriage for Ann Jane Teare & John Watts on 3 Oct.1878 Patrick.

So if his birth date of 26 May 1878 was correct, as given in Canada, he was born pre-marriage, and would not be in the IGI bapts under "Watt".

However Brian Lawson's birth cert index has:
WATTS, Arthur Edward 24 Nov 1878 Pat WATTS, John Edward, TEARE, Ann Jane. [And other children of this couple.]

They can't have had one son born 26 May 1878, and another one born 24 Nov 1878.

Sue