Jan Stephanus van der Lingen, son of Reverend Gottlieb Wilhelm
Brueckner van der Lingen and his wife Susanna Sophia, born Moll, attended
school in Kroonstad, where his education was interrupted when his family were
sent to East London during the Anglo-Boer War (1899-1902). Upon his return to
Kroonstad he continued his education, but left school to join an engineering
firm as an apprentice electrician. By the time he qualified he had developed an
interest in the natural sciences and enrolled for a correspondence course
offered by the Franklin Institute in the United States. As a result he was
invited to continue his studies in the United States. However, his father would
not let him go before he had passed the matriculation examination of the
University of the Cape of Good Hope. This he achieved through the High School
in Kroonstad in 1907, after which he decided to continue his studies in applied
mathematics and physics at Victoria College (later the University of
Stellenbosch). He was awarded the degree Bachelor of Arts (BA) with honours in
applied mathematics by the University of the Cape of Good Hope in 1911.
After teaching for some time at Cradock, Eastern Cape, he
acted as a temporary assistant in the Department of Applied Mathematics at the
South African College (from 1918 the University of Cape Town) during the fourth
term of 1912. He then received a bursary which enabled him to proceed to Zurich
to study agricultural engineering. There he came under the influence of the
Nobel Prize winner Max von Laue, who encouraged him to conduct research in
X-ray crystallography. As a result of over-exposure to X-rays he had to return
to South Africa to recuperate and was prevented from continuing his studies in
Zurich by the outbreak of World War I (1914-1918). In the beginning of 1915 he therefore
accepted an appointment as lecturer in applied mathematics at the South African
College, under Professor Alexander Brown*. There he remained until 1920, when
he was awarded a bursary by the Johns Hopkins University in Baltimore, United
States, where he obtained a doctoral degree in 1921 with a thesis entitled The fluorescence of mercury vapour. His
thesis was published in the Astrophysical
Journal that same year. Meanwhile he had started research in biophysics and
briefly became the head of a newly created sub-department of biophysics in the
medical school of Johns Hopkins University. He retained an interest in
biophysics, especially in radiology, for the rest of his life.
Van der Lingen remained at the University of Cape Town until
1930, when he was appointed head of the Department of Physics at the University
of Pretoria. That same year the government asked him to become the chairman of
the newly created Fuel Research Board, a position he held until at least 1939.
Van der Lingen had an outstanding ability to design his own
experimental equipment and several of his designs came into general use in
physics laboratories. His interest was mainly focused on the general principles
underlying physical phenomena, leaving the investigation of the details to
others. He had a thorough knowledge of the mathematical aspects of his subject,
which he taught with enthusiasm; also a restless mind and a high opinion of
himself. His fifty or so scientific publications covered a wide range of topics. Among others the following papers by him
appeared in the Transactions of the Royal
Society of South Africa: 'On the space lattice of liquid crystals' (1915), 'On
the lines within roentgen interference photograms' (1916), 'Heating and cooling
apparatus for roentgen crystallographic work' (1916), 'Note on the ionisation
produced by degenerating nerve-muscle preparations' (1917), and 'On hyalite' (a
transparent variety of opal; with A.R.E. Walker*, 1922). He was elected a
Fellow of the Royal Society of South Africa in 1922 and served on its council
from 1923 for some time. Many later papers by him were published in the South African Journal of Science,
including 'On the planetesimal hypothesis' (1924), 'On the supposed
photo-activity of cod liver oil' (1926), 'A universal gas-pressure apparatus
for comparative spectroscopy' (1936), 'Absorption spectra of olive oil in the near
infra-red' (1936), and 'A modification of the Jaeger surface tension apparatus'
(1936). He became a member of the South
African Association for the Advancement of Science in 1912 and was president of
Section A in 1928. He was also a Fellow of the Institute of Physics and became
a member of the South African Chemical Institute in 1931.
Van der Lingen was married to Enid Christine Wilcocks, with
whom he had two sons and a daughter.
