A Tangled Web, More Interrelationships

In my previous blog posting called A Tangled Web, I describe some of the tangled interrelationships between some of my distant cousins. In this missive, I continue, describing an interesting case of first cousins marrying. All of us necessarily have ancestors who were related. Indeed, if you double the number of your ancestors on each generation going back, you eventually reach a point where the number of ancestors exceeds the total population of the world. Which means that at some point, the rate of increase in the number of ancestors slows down while ancestors marry relatives, close or distant.

That said, in my own pedigree, I've so far not found any cases of ancestors who were related. But I suspect I'll find at least one case of that, since on the German side of my pedigree, I'm a descendant of four separate lines of Wulff's. Mind you, Wulff is a very common name in Mecklenburg-Schwerin.

But there are cases of cousins marrying among others in my database, among my distant cousins. In this study, we start with the central person of my previous essay, Willemina Woutrina Moll (1808-1882). In the following drop-chart, most people lived in the village of Velp, east of Arnhem, in the south-eastern corner of Gelderland.

Descendants of Jan WIllem Moll and Neleke Looijse. (Not all children shown)

Consider a niece and a nephew of Willemina. Willemina's nephew Jan Willem Moll (1849-1915) married Willemina's niece, and Jan Willem's first cousin, Catharina Moll (1844-1921). Jan Willem was the son of Willemina's brother Jan Willem Moll (1819-1851) and Geertje Gerritsen. And Catharina was the daughter of Willemina's brother Lubbertus Moll (1812-1877) and Everdina de Roos.

But there's more. Jan Willem and Catharina had a son, Jan Willem Moll (1883-1959) who married his first cousin Johanna Wilhelmina Moll (1883-1955), daughter of Hendrik Moll (1851-1903) and Woutje Snellink. Hendrik was a brother of Catharina Moll.

Now consider the pedigree of the youngest children in this drop-chart: As the children of first cousins, they have six great grandparents, instead of the usual eight. In addition, since one set of grandparents were first cousins, they have just ten great great grandparents, instead of the usual sixteen.

There's one more example of a tangled interrelationship in this chart: Geertje Gerritsen married again after the death of her first husband, to Jan Matser. One of their children, Johanna Matser married another Moll, Jan Willem Moll (1850-1937).

A Tangled Web

When researching my distant cousins, I normally try not to put much effort into the in-laws, and devote most of my time into finding blood relatives. I suspect that's true for others as well. I do try to find birth, marriage, and death records for the spouses of blood relatives, but usually that's as far as I go. However, when I see the same names crop up again and again, I can't help but investigate the interrelationships between various in-laws.

In this essay, I consider some distant cousins who lived in the south-east corner of the Dutch province of Gelderland, east of Arnhem and south of the Veluwe, in the villages of Velp, Angerlo, Lathum, Hummelo, and Westervoort. This is an area where it seems like everyone knew everyone, where many people seem to be related, if not by blood, at least by marriage. Let's look in particular at the immediate family of my distant cousin Willemina Woutrina Moll (1808-1882).

Family of Willemina Woutrina Moll (Not all relationships shown)

Willemina was married twice, in 1829 to Barend Thomas van Zadelhoff (1793-1832) and in 1833 to Nicolaas van Zadelhoff (1792-1872). Barend Thomas died before the birth of their third child. Seeing the same surname twice was certainly enough to raise my curiosity, and a bit of investigation revealed that the two men were first cousins. The children of Barend Thomas and of Nicolaas had an interesting relationship since they were related in two ways. First, they were half siblings. Second, they were second cousins. That means they shared six of eight great grandparents: All four of Willemina Woutrina's grandparents, plus the two common grandparents of Barend Thomas and Nicolaas.

But there's more to this tangled web. The two daughters of Barend Thomas and Willemina Woutrina, Catharina van Zadelhoff (1830-1897) and Berendina Theodora van Zadelhoff (1832-1914), married two brothers Lambertus Wentink (1825-1899) and Jacobus Reinerus Wentink (1832-1914), respectively. In fact, the two weddings happened on the very same day, with the same four witnesses. There were children from these two marriages. Whenever two siblings marry another pair of siblings, their children are known as "double cousins". Normally, first cousins share two grandparents. However, double cousins share all four grandparents.

The same pattern repeats with the children of Willemina Woutrina and Nicolaas, not just once, but twice. And in one of those cases, three siblings marry a trio of siblings. We have Nicolaas van Zadelhoff (1839-1909), Wanderina Margaretha van Zadelhoff (1842-1869), and Barend van Zadelhoff (1850-1914) marrying the three siblings Elsken Smit (1841-1904), Hendrik Smit (1839-1890), and Christina Smit (1844-1892). And we have Hendrik van Zadelhoff (1844-1875) and Antonica Geertruida van Zadelhoff (1854-1936) marrying the siblings Jacomiena Ploeg (1842-1933) and Wessel Ploeg (1838-1929), respectively.

The interrelationships don't end with what's depicted on the diagram. For example, Barend van Zadelhoff was married twice. His second wife was Elske Geurdina Kets (1835-1931), a first cousin of his first wife Christina Smit.

How far does one go when investigating in-laws? It's entirely up to you. With almost all the records available on-line, it's now much easier to see the tangled web of interrelationships of our ancestors.

(You can read more in a followup at A Tangled Web, More Interrelationships.)

My (Distant) Kamerlingh Onnes Cousins

As we all know, genealogy can take us anywhere. We don't know what we'll find when exploring down some dark alley. A few days ago, I was researching some distant Moll Schnitzler cousins when I came across a photo from 1928 of the staff of the Bureau voor Handelsinlichting in Amsterdam. The man standing at left was A.J. Moll Schnitzler. The surprise came when I looked at the names of the people. The man sitting in front of Anthony Julius was O. Kamerlingh Onnes.

25th Anniversary of the Bureau voor Handelsinlichting, 1928.

Now then, "Moll Schnitzler" is not a common name. Everyone with that name is a distant blood cousin of mine. Likewise, with the exception of one person, everyone named "Kamerlingh Onnes" is also a distant blood cousin of mine. A bit of investigation revealed that Onno Kamerlingh Onnes was my 4th cousin twice removed. I was intrigued, and decided to do a side trip into the Kamerlingh Onnes family.

Some twenty years ago or so, I received an e-mail from a distant cousin stating that I was related to not just one, but two Nobel Prize recipients, Hendrik Antoon Lorentz (second cousin twice removed) and Heike Kamerlingh Onnes (4th cousin twice removed). As someone interested in science, I was surprised and honored to be related to two of the most significant scientists of the early 20th Century.

Heike (1853-1926) was the oldest of seven children of Harm Kamerlingh Onnes (1819-1880) and Anna Gerdina Coers (1829-1899). (I'm related via the Coers family.) Heike is best known for his research into the properties of matter at extremely low temperatures, which earned him his Nobel Prize. In particular, he was the first to liquefy helium and the first to observe the property of superconductivity.

Onno (1861-1935), pictured above, was the fifth child of the family, and was the director of the Bureau voor Handelsinlichting. However, later in life he became an artist, following in the footsteps of other close family members.

Their brother Menso (1860-1925) was a relatively famous portrait artist. Among his subjects were professors at the University of Leiden, including his brother Heike and Hendrik Lorentz. One of his more famous portraits hangs in the Stedelijk Museum de Lakenhal in Leiden, portraying his sister Jenny (1863-1926).

Hendrik Antoon Lorentz, painted by Menso Kamerlingh Onnes

Jenny Kamerlingh Onnes, painted by her brother Menso

Menso's son Harm (1893-1985) was also an artist, working in a variety of media, including drawings, watercolors, oil paintings, and ceramics. Some of his designs for stained-glass windows depict discoveries and instruments of contemporary physicists, including, again, Lorentz.

Fall trees in the city park, painted by Harm Kamerlingh Onnes

Stained-glass windows designed by Harm Kamerlingh Onnes depicting the Zeeman effect with explanation by Hendrik Antoon Lorentz

The connections to the arts do not end there. For a time, Menso shared a studio with artist Florist Verster (1861-1927), who in 1892 married Menso's sister Jenny. Verster was known for his bold and colorful still-life and landscape paintings, many of which hang in museums in the Netherlands.

Of the other three siblings, one died in infancy and the others emigrated to North America and India.

Throughout this missive, I've mentioned physicist Hendrik Lorentz. Clearly, there were connections between Lorentz and the Kamerlingh Onnes family. But it's not clear whether or not they knew that they themselves were distant cousins. Lorentz was a fifth cousin to Heike and his siblings. Getting back to the photo that initiated this diversion, Onno Kamerlingh Onnes was not a blood relative to his coworker Anthony Julius Moll Schnitzler. However, they also probably did not know that a distant great grand uncle of one was married to a distant great grand aunt of the other.

For additional details about this family, start with my page on their father, Harm Kamerlingh Onnes.