Would it be reasonable to assume that twins would have consecutive Birth Cert numbers? I have cert # 2242, dated 28 Feb 1894, for the birth of Thomas CASEY on 06 Feb 1894 in Bklyn. I'm seeing other Family Trees on Ancestry indicating he might have had a twin (Francis) although I have not found any evidence of that while searching the NYC Municipal Archives.
I am aware of what the 1900 and 1920 census records show for these brothers; I'm trying to determine if they were twins.
Any advice will be appreciated.