How's Your Ahnentafel ?

“Where would we be without prime numbers, Grandpa ?”
That’s the kind of question I have to cope with from my grandson, now in his last year at school studying maths and physics. I’ve even deserted my Iain Banks & Lee Child books in favour of Brian Greene, “The Hidden Reality” (well hidden indeed for a pensioner), to try and repair our communications!

In the latter book the author always chooses the difficile word (see, it’s catching), so in recent genealogy correspondence when “Ahnentafel” was mentioned I thought 'here we go again; or have I missed a village near Dumfries where I was born' ?
As it turns out, I should have known about an “Ahnentafel”, being a keen genealogist, everybody in the Society should know, so here goes, with the explanation.

An “Ahnentafel” is a German word for “ancestor table” and is a list of one’s ancestors, so constructed, that it is easy to calculate the various relationships.
The first “Ahnentafel” was published by Michael Eytzinger in 1590 - see the illustration. He was an Austrian historian and the same numbering system is sometimes called the “Sosa-Stradonitz System” named after the Spanish and German genealogists, Jerome de Sosa (1676) and Stephan Kekule von Stradonitz (1896).
In an “Ahnentafel” numbering system the base person is assigned the number one. The father of each person is assigned a number equal to double the child’s number. The mother of each person is assigned a number equal to double the child’s number plus one. As a result, the number of any child is one- half that of their parent, ignoring any remainder.
Apart from the subject, who can be male or female, all even-numbered persons are male and all odd-numbered persons are female. Please no sexist comments!

For the first four generations, the numbers assigned a given person and their ancestors reflect the following relationships.
Decimal                                          Binary
1.    Person                                 1          
2.    Father                                  10
3.    Mother                                11
4.    Paternal grandfather        100        
5.    Paternal grandmother      101
6.    Maternal grandfather       110
7.    Maternal grandmother     111
8.    Great-grandfather             1000   father’s father’s father
9.    Great-grandmother           1001   father’s father’s mother
10.    Great-grandfather             1010   father’s mother’s father
11.    Great-grandmother           1011   father’s mother’s mother
12.    Great-grandfather             1100   mother’s father’s father
13.    Great-grandmother           1101   mother’s father’s mother
14.    Great-grandfather             1110   mother’s mother’s father
15.    Great-grandmother           1111   mother’s mother’s mother
For the binary write down the digit “1”, this represents the subject, and, writing from left to right write “0” for each father and “1” for each mother in the relation, ending with the ancestor of interest.
The result will be the binary representation of the ancestor’s “Ahnentafel” number.
As the example above, great-grandmother No.15 = 1111
To simplify your calculation of the conversion, in “Google”, type in, 15 to binary, to get the answer 1111 etc.


As they say in all the best books; for the “mathematically inclined reader” there are a number of websites where you can study the full application.
I just want to bring this “Ahnentafel” system to your attention.

This is a guest blog by Strath Stewart.

Edinburgh Register of Aliens

A few days ago, Strath from New Zealand alerted readers of our forum to a potentially very interesting source of information.

It is a transcription, I imagine, of core information in Edinburgh Registers of Aliens recorded between 1794 and 1825.

It lists first names and surname, age, place of birth, residence, residence - pre-arrival, residence in Scotland, occupation, port of arrival, date of arrival, date registered, notes.

The first page of the PDF says
"....The first is a handwritten volume of declarations given in by foreigners before the Magistrates as to their origins, occupation, length of time in the Country and the intended duration of their stay in Edinburgh. Most declarations were made in 1794.....
The Registers in the second series are bound volumes of pro-formas of questions to be asked and answered before Magistrates regarding the name, origins, status, occupation, age and intentions of foreign visitors. Also given in these volumes, are the current addresses of the respondents as well as the names of the British ports through which they first entered the Country. They cover the period 1798-1825."

These were troubling times, and clearly the authorities needed to know more about resident foreigners. France declared war on Britain on 1st February 1793, in early September, the French National Convention began the 'Reign of Terror' measures to uphold the principles of the French Revolution.

In 1795, Napoleon had his first success in invading Italy, by capturing Milan; and other cities and areas were captured subsequently. The war between Britain and France ended in May 1802 with the the treaty of Amiens, though it began a year later when Britain declared war on France. In May 1804, Napoleon Bonaparte was proclaimed Emperor of France, though he wasn't crowned until December; and in 1805 he was crowned King of Italy.

Most of these foreigners were from France, Italy and the USA, but others came from Austria, Brazil, Denmark, Switzerland, Finland, Germany, Holland, Hungary, Latvia, Lithuania, Norway, Poland, Portugal, Russia, Sweden, Switzerland.

There were a lot of medical students, almost all from the USA, and some people had quite unusual occupations, though there none listed as spies.

Not surprisingly, all their addresses were in or around Edinburgh; but their ports of arrival were all over Britain.

Clearly, this resource is full of interest.

I suggest you download the Register of Aliens for yourself.

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