Afternoon Maggie

The name/s McDow, MacDow etc; are virtually unknown in Scotland.

I have checked on both Family Search and particularly on Scotland's People, with very few examples showing up.

http://www.familysearch.org/Eng/Search/frameset_search.asp

http://www.scotlandspeople.gov.uk

There are practically no occurrences in the OPRs (Old Parish Records) under any of the headings over the period 1553 to 1855 on Scotland's People, the most comprehensive site for Scottish BMD, Census and Wills.

The Census returns have some showing up around the 1870s particularly, at the time of the expansion of the railways, suggesting that Ireland rather than Scotland may be the origins. (The Irish navvies building originally the canals then the railways in the UK.)

This may be reinforced by your extract from the Montreal church records of-

"Thomas O Dowd".

Dowd and its variants tends to be an Irish name, frequently using the Irish contaction for "son of" in the form "O' ". Compare with O'Donnell etc.

So could it be that this ancestor was actually

"Thomas O'Dowd"?

Alex Dow