Quarterly Journal of the Royal Astronomical Society, 35:2 231 (1994).

"INGE LEHMANN: REMINISCENCES" by Bertha Swirles, Lady Jeffreys

It was not until my marriage to Harold Jeffreys in 1940 that I knew of the importance of Inge Lehmann's work in observational seismology and for the next five years it was not possible for them to communicate with each other. He must have had letters from her in the 1930s but I regret that these have disappeared. Although he was an undergraduate at Cambridge during her time in Newnham College I believe that they did not meet until some years later. The first impression I had of her was misleading. With the kindest of intentions she sent us some eggs, packed in sawdust, and they did not travel well. I first met her in 1948 when I accompanied Harold to the IUGG meeting in Oslo and we met at later meetings up to Berkeley in 1963. There are many entries under Lehmann in the index to Volume 2 of Harold Jeffreys's Collected Papers and these span the period from 1934 to 1966. Now at the age of 90 I must be the oldest of the Fellows that have known her.

In 1958 after the IAU meeting in Moscow we spent a few days in Copenhagen. Inge arranged for us to stay at a pension near Kastelsvej. This was kept by Frøken Have whose former Pension at Tranglen 2 was well known between the Wars to physicists at Niels Bohr's Institute. As I had stayed with her in 1930 we recognized each other with great pleasure. Inge took us to the Deer Park and to her summer cottage at Holte, where, already aged 70, she mounted a ladder to her bedroom. I believe that she continued this practice for some years after that. In 1964 our visit to Lamont overlapped with hers but we were not present when the honorary doctorate was conferred on her at Columbia.

In 1987, when C.M.R.Fowler was writing The Solid Earth (CUP 1989) she asked me for information about G.Rasch, whose proof of the Herglotz-Wiechert equation is quoted by Harold Jeffreys in The Earth. Inge was approaching her century but I wrote to her and in a letter dated 22 April 1988 Erik Hjortenberg wrote, "A few days ago Dr Lehmann found a letter from G.Rasch dated November 9 1934, where he gives her the mathematical proof in the same form as he had previously given to your husband. She asked me to send that letter to you and remarked that you need not return it. I took a copy ... ". The letter is in Danish but it consists largely of equations. Rasch was interested in mathematical statistics, not seismology.

On a visit to Cambridge in the 1960s Inge was shocked to find me using thick breakfast cups and saucers in a pattern imitating Royal Copenhagen, the first patterned ware that appeared in England after the war. In 1969 during the Conference in Copenhagen she came from Kastelsvej to our pension near Kongens Nytorv to bring me some of the real thing, almost too delicate to use. I also treasure a tea-cosy embroidered by her mother.

Inge had great energy, both mental and physical. She loved mountains, particularly in Switzerland. In the citation for the Bowie medal in 197l Francis Birch drew attention to the economy of the title of her 1936 paper, " P' ", and provided what could be a fitting epitaph, describing her as "the master of a black art for which no amount of computerizing is likely to be a complete substitute".

Bertha Swirles Jeffreys, Quarterly Journal of the Royal Astronomical Society, 35:2 231 (1994).