Louisa Wathen, father's name?

[molar]

My g.g.grandmother married John Carl Albert Voigt in Bristol in 1867.
Her father was named as John Wathen grocers asst. On the birth cert of the only Louisa reg at the relevant time the father is named as Henry occ labourer. mother Jane Daw. BVRI shows Louisa christened in May 1847 father John,mother Jane. Henry Wathen married Jane Daw in 1840 in Bristol and gave his occ as cheesedealer, father Charles occ traveller. In 1871 Henry and Jane are living in Bristol, also with them was their married daughter,Maria Jane and grandson and it says Henry was born in Bloomsbury London,his age given as 54. occ grocers asst. In 1891 there is a Henry Wathen living in Salford Manchester age 72 born London, it looks like he had married again to a woman 30 years younger. Louisa and John Carl Albert also had moved to Manchester.  I'm sorry if that was long winded but my question is do I look for the birth of Henry or John everything seems to point to Henry but why would Louisa say her father's name was John? Any help much appreciated.
Regards

[trish251]

Both sisters are on the IGI (extracted entries) with father Henry viz
Maria Jane Wathen 
Christening:  20 OCT 1844   Holy Trinity, Bristol, Gloucester, England
   Father:  Henry Wathen
  Mother:  Jane

Louisa Wathen 
Birth:  03 MAY 1847   Holy Trinity, Bristol, Gloucester, England
Christening:  28 NOV 1852   Holy Trinity, Bristol, Gloucester, England
Father:  Henry Wathen   
Mother:  Jane

My  only thought would be that the father was perhaps known as "John". My father's name is Neville, but throughout his life he has been called Mick. Many of his friends refer to him as Michael, assuming this to be his correct name. Louisa may have assumed John was his name, if this was the name she had always heard him called??
It could also be an error by the Minister completing the certificate - using husband's name rather than father?

[Welsh Jen]

I think Trish is right. I have ancestors who were known by their 1st and middle names. My father is also the same. He may well have been Henry John (or John Henry)