WHAT’S IN THE AIR? ERIC HALLIDAY, LIGHTNING AND AIR POLLUTION

By Jane Carruthers FRSSAf

Johannesburg’s violent thunderstorms are legendary and provide summertime drama and excitement. Even during this current (2015/2016) El Niño season, loud claps of thunder and frightening bolts of lightning have accompanied many an evening storm, sometimes with a mere pitiful rain-shower to follow. Johannesburg’s reputation as the lightning capital of the world has drawn some of the country’s most outstanding scientists to the study of this complex phenomenon. Of course, the early experiments of Benjamin Franklin in the 1750s that linked electricity and lightning were a precursor to the scientific study of lightning, but the field was taken much further in South Africa under the leadership of Basil Schonland in the 1930s, a story that is well told by Brian Austin in his biography of Schonland.Lightning over Johannesburg

Less well known is the career of Eric Clifford Halliday (1904-1996), a man greatly influenced by Schonland and his collaborator on lightning research. Halliday was a Fellow of the Royal Society of South Africa and a leading figure in the CSIR in the 1950s and 1960s. His varied accomplishments on the topics of lightning research, measures and standards and in the inception of air pollution study and control are worth noting.

In 1922, as a student at the University of Cape Town, Halliday was inspired by Schonland who was a lecturer at UCT to appreciate that physics was no routine study, but an exciting discipline of innovation. Lightning was one of the topics then being investigated by Schonland through experimentation to determine exactly how the phenomenon worked. By 1932, with his PhD behind him and having commenced his career in 1926 as a young lecturer at the University of the Witwatersrand (Wits), Halliday began to conduct his own research, teaming up with Schonland. During the summer storm seasons the pair and their assistants (that included their wives) spent long periods on the roof of the physics department at Wits with various instruments of their invention that enabled them to monitor the paths of lightning. The major instrument they employed was the Boys Camera, named after British physicist Sir Charles Boys FRS, that was able to take multiple photographs at extremely high speed utilising a rapidly rotating lens or film so that the dynamics of the lightning flash were recorded in time on the film, thus tracking a bolt of lightning visually. Halliday built a sophisticated electrically-driven Boys camera and this, together with his capillary electrometer and electric field sensor, enabled some of the work on which Schonland’s influential book, Atmospheric Electricity (1932) was based.

In 1933 Halliday published his findings ‘On the propagation of a lightning discharge through the atmosphere’ in the Philosophical Magazine. With Schonland’s backing, Halliday spent 1933 in Cambridge, mainly at Cavendish, and in 1934 he worked at King’s College, London, under Edward (later Sir Edward) Appleton, the 1947 Nobel Prize winner for physics who had proved the existence of the ionosphere in the 1920s. While in England and furthering his research on lightning related physics, Halliday developed his own cloud chamber, a particle detector for detecting the presence of ionizing radiation. This methodology had been invented by Charles T.R. Wilson, earning him the 1927 Nobel Prize in physics. Halliday was clearly at the cutting edge of experimental particle physics and singled out by his peers for a very bright future as a scientist.

After his years in England, Halliday returned to South Africa and to his position in the Wits physics department where he was extremely productive. He continued his lightning research and also studied the Kennelly-Heaviside layer, one of the several layers of the Earth’s ionosphere, and one that has implications for radar – an extremely important scientific development of World War II.

After the War Jan Smuts’s plan for a Council for Scientific and Industrial Research (CSIR) became a reality: it was headed by Schonland (See Fragments of History, July/August 2015). In 1945, although he was not to linger at the CSIR after the National Party came to power in 1948, Schonland persuaded many of South Africa’s top scientists to join the CSIR. Halliday, generally referred to as ‘Doc’, was one of them and he was to remain with the CSIR, in the National Physical Laboratory (NPL – after 1957 called the National Physical Research Laboratory NPRL), until his retirement in 1970.

As McDowell describes, a physicist in that era ‘was expected to be able to adapt to any task within the scope of that discipline, be it nuclear, optical or metrology. As [S. Meiring] Naude’s second in command, Halliday found himself in charge of nuclear physics, biophysics, heat and physics of matter.’ I first met Halliday through mutual friends in the late 1970s, around the time that he was awarded the 1978 physics Gold Medal of the South African Association for the Advancement of Science and avidly listened to his scientific reminiscences.

Halliday is remembered for his work at the CSIR in two main categories. One is his role in standards and measures. McDowell refers to him as ‘the father of national standards in South Africa’. When the CSIR was new, Halliday visited comparable institutes and councils of scientific research in Europe and the USA, and one of the topics of investigation was around establishing standards of mass, pressure and length. However, the matter of standard measures was confusing as the Standards Act 24 of 1945 had established the South African Bureau of Standards (SABS). However, Halliday believed that, as an institution for fundamental scientific research, the role of the CSIR was to develop and maintain primary standards, leaving secondary standards and similar repetitive work to the domain of the SABS.

From 1947 to 1964 (when South Africa became the 40th signatory to the International Metre Convention in Paris) and when Halliday attended the 12th International Conference on Weights and Measures in October that year, standards were the responsibility of the NPL. This was, of course, the period during which South Africa was planning to change from imperial (and Cape) to metric measurements. In 1964 most standards were incorporated into a new Division of Precise Physical Measurements (PPM) within the CSIR that was managed by Halliday.

Halliday did not, however, neglect his interest in the atmosphere, but it shifted from the physics of the ionosphere and lightning to the study of air pollution. In 1960, he founded an Air Pollution Research group in the CSIR. A carbon monoxide measuring programme was started at Cape Point in collaboration with the Max Planck Institute in Germany. No doubt South African science in this regard was influenced by the situation in Britain where the Clean Air Act had been passed in 1956. Halliday’s guidance can be seen in South Africa’s Atmospheric Pollution Prevention Act 45 of 1965 and he became one of the first Air Pollution Control Officers appointed in terms of the Act. While London’s infamous 1952 smog was the catalyst for Britain’s concern with air pollution, it was the situation around Witbank’s collieries that spearheaded the move to control pollution in South Africa. Indeed, it is sad to record that, according to Greenpeace, decades of legislation has not had the intended consequence and Witbank’s airKendal power station near Witbank remains among the dirtiest, if not the dirtiest, in the world. Naturally this impacts on the health of those who live in the vicinity as well as on climate change more broadly. South Africa’s first National Air Pollution Committee met in 1955 because it was clear that pollution control cannot be a local problem but requires tackling at a national level. Halliday was deeply involved in discussions about air pollution control and contributed greatly to the Commission of Enquiry established by the Department of Health. This was politically fraught as it seemed at times that government was protecting polluting industries ahead of its responsibility for the health and safety of citizens.  Halliday criticised this ‘cautious attitude’ of government and its concern for industrialisation at all costs and, no doubt he would be disappointed to see how far South Africa still has to go to contain the air pollution that is concomitant with coal-fired power stations. In 1969 a National Association for Clean Air (NACA) was formed with Halliday’s strong support in his position as Chair of the Air Pollution Research Fund. In 1970 NACA became affiliated to the International Union of Air Pollution Prevention Associations, and a full member in 1973. Under Halliday’s editorship, the first issue of The Clean Air Journal appeared in 1971.

Air quality currently falls within the portfolio of the Minister of Environmental Affairs although many other departments are interested parties with responsibilities for mitigating pollution. The governing legislation is the National Environmental Management: Air Quality Act 39 of 2004 and the latest and very complex amendment to the Republic’s 2007 National Framework for Air Quality Management was published on 29 November 2013 (Government Notice 919).

 

 

REFERENCES

Austin, B., Schonland: Scientist and Soldier (Johannesburg: Witwatersrand University Press, 2001).

Grange, G.H., ‘National Association for Clean Air: The first twenty five years 1969-1994’, The Clean Air Journal 9(2), 1994.

Halliday, E.C., ‘On the propagation of a lightning discharge through the atmosphere’, Philosophical Magazine S7, 1933, pp.409-420.

Kingwill, D.G., The CSIR: The First 40 Years (Pretoria, CSIR, 1990).

Murray, B.K., Wits: The Early Years. A History of the University of the Witwatersrand, Johannesburg, and its Precursors, 1896-1939 (Johannesburg: Witwatersrand University Press, 1982).

McDowell, M., The National Metrology Laboratory of South Africa: The First 50 years

(1947-1997) (Pretoria: CSIR, The National Metrology Laboratory, 1957).

Schonland, B., The Flight of Thunderbolts (Oxford, Clarendon Press, 1964). First published 1950.

Singer, M., ‘Changing conceptions of South African coal-based pollution, with special reference to the Witbank coalfield, 1906-1978’, M.A. dissertation, University of the Witwatersrand, 2010.

Singer, M., ‘Changing the atmosphere: Shifting conceptions of air pollution in South Africa, with special reference to the Witbank coalfield, 1948-1978’, Pollution Atmosphérique, Climat, Santé, Société, No. 222, 2014.