Note: Geni.com reports date of death 1929-10-27. An obituary confirms year 1928 that is reported elsewhere: The "scientist and author, who had lived in California since 1874, died recently in Oakland at the age of 98." A "surveying geometrician for the Belgian government", Van der Naillen moved to the US in 1859 and "was a civil engineer during the rebellion". Beside later studies of wireless telegraphy, X-rays, and radio-activity, he served for a time as president of the California Psychic Research Society. --"A Long-Lived Scientist", Los Angeles Times 1928-11-04 pB4