and the automatic scanner. The prototype became the basis for the Diasonograph, which became the first commercially produced machine in 1965. Around this time, Donald gave a series of lectures in the US. In 1960 he, MacVicar, and Brown demonstrated their scanner at a medical exhibition in Olympia, London, England. During this period Donald and his team scanned hundreds of patients who were both pregnant and non-pregnant, and Donald found that fetal echoes were visible at an early stage, which led to the distinction between a case of threatened abortion and a case with a hydatidiform mole, both with bleeding. The image showed a speckled picture, whereas the fetus produced strong echoes floating in space containing liquid. Donald received many requests for differential diagnosis, so the work was moved to the X-ray department. Meanwhile, Donald noticed the very sharp echoes that were being produced at the sides of an infant's head, which led to the use of a hand-held probe and the A-mode scanner to detect the presentation of the fetus. Donald's ward sister at Rottenrow, Marjory Marr, used the technique to test doubtful cases in her antenatal ward and was able to tell Donald in advance where the fetus lay, which led Donald to think about measuring the distance between the echoes as an index of the head by using the biparietal diameter. Experiments proved the idea was feasible. Duggan created a ranging unit in which the distance between echoes could be calculated in centimetres and millimetres. James Willocks, a physician who worked with Donald in the same department at Rottenrow, undertook many hundreds of experiments using the new technique resulting in errors of less than 2% over 75% of cases. The use of serial measurements of the fetal head was the first study to use ultrasound to measure fetal growth. Donald presented the results of the experiments at a meeting of the Royal Society of Medicine on 12 January 1962. By 1970, Donald could image fetal development during pregnancy using the Diasonograph, which led to new criteria diagnosing pregnancy failure, and resulted in his techniques being widely adopted as standard clinical practice in the 1970s. Queen Mother's Maternity Hospital The idea of a new maternity hospital had been on Donald's mind when he was asked what plans he had should he be appointed during his interview for being hired as a professor. He was in charge of a