Miss M. Giles resided at Mahalapye, Botswana, where she collected meteorological observations for many years. A summary of her observations was published by A.H. Wallis* in Meteorological observations: Mahalapye; from the records of Miss M. Giles, 1917-1943 (Cape Town, 1943, 11 p). The pamphlet contained tables of monthly means of air temperature, humidity of the atmosphere, and rainfall for each month during the period 1912-1942.
During February and March 1923 Miss Giles regularly observed antisolar rays at Mahalapye - shadow bands cast across the sky by irregularities of the western horizon immediately after sunset, which appear to converge at a point on the eastern horizon opposite the sun. She wrote a description of the rays for Wallis, which he included in his note on "Anti-solar rays" published in The Meteorological Magazine (June 1923, Vol. 58, pp. 105-106).