 Ir. Johan Maxmilliaan "Jan" Dijkgraaf, son of Drs. Pieter Cornelis "Piet" Dijkgraaf and Priska Hildegarde Dorothea Exner.Born 24 Jul 1904 's-Gravenhage, died 21 Jul 1972 Rotterdam, age 67 years, cremation 26 Jul 1972 Rotterdam. Occupation: werktuigkundig ingenieur/medewerker Unilever (o.a. Calvé Delft) Marriage notice 13 Feb 1931 Rotterdam. Married 24 Feb 1931 Wassenaar, age 26 years Divorced 22 Aug 1959 Wassenaar (married 28 years) from:  Johanna "Han" Hendriks, age by marriage 26 years, daughter of Petrus Dirk Herko Hendriks Ridder in de Orde van de Nederlandse Leeuw and Anje Bos.Born 31 Aug 1904 Groningen, died 15 Sep 1996 's-Gravenhage, age 92 years Children: 2. Pieter Cornelis DijkgraafBorn 11 Nov 1937 's-Gravenhage, died 14 Nov 1937 's-Gravenhage 3. Otto DijkgraafBorn 26 Nov 1938 's-Gravenhage, died 05 Feb 1940 Wassenaar, age 1 years 4.  Levenloos geboren DijkgraafBorn 23 Jan 1947 's-Gravenhage at 15:45 hour, died 23 Jan 1947 's-Gravenhage at 15:45 hour | |||
| 2nd marriage Ir. Johan Maxmilliaan "Jan" Dijkgraaf, son of Drs. Pieter Cornelis "Piet" Dijkgraaf and Priska Hildegarde Dorothea Exner. Married 02 Aug 1960 Rotterdam, age 56 years (married 11 years) to: Maria Josephina Reinilda "Mia" Smeets, age by marriage 51 years, daughter of Peter Franciscus Smeets and Marie Nathalie Lambert.Born 11 Feb 1909 Antwerpen (B.), age 116 years | |||