SOSA-STRADONITZ NUMBERING SYSTEM
The genealogy tables are based on the Sosa-Stradonitz system, whereby every person is allocated a specific number working back from No. 1, the subject of the table. Thus that person's parents become Nos. 2 and 3, the grandparents Nos. 4 to 7, the great-grandparents Nos. 8 to 15 and so on. Under this system all males will have even numbers and all females odd numbers.
To find the father of any person, simply double their reference number and look it up in the table. The mother can be found by adding 1 to the father's number. Similarly, a child's reference number can be found by halving the father's number (or by subtracting 1 from the mother's number and then dividing by two). In the information about any individual the reference numbers and names of both parents are included where known.
DUAL DATES BEFORE 1752