Alexander, Thomas A. (1847–1933), professor of civil engineering, was born 2 May 1847 in Maryhill, Glasgow; his parents' names are not known. Educated at the Normal School in Cowcaddens, Alexander entered Glasgow University in 1867, where he won prizes in mathematics, mechanics, geology, and civil engineering, and graduated with a certificate of proficiency in engineering science (1870). The next few years were presumably spent in Scotland practising his craft, but in 1877 he relocated to Japan to teach at the College of Technology in Tokyo, a newly established institute to promote western technology in the east. Alexander was the first instructor appointed to the civil engineering department, where he taught surveying technology, technical drawing, mathematics, and civil engineering, and in 1879 he became the first teacher of bridge engineering. In March 1879 he was offered the professorship of civil engineering, which he gladly accepted (1879–86), but when the college was merged with the Tokyo Imperial University's department of civil engineering, he declined to move (March 1886), choosing instead to return to Scotland. For his services to Tokyo, he was made a member of the 4th order of Meiji by the emperor of Japan.
Alexander's homecoming proved short-lived, for in 1887 he was appointed to the chair of civil engineering at TCD, heralding a new era in the history of the department. He was head of the department for over thirty years (1887–1921), during which time he proved himself to be a capable administrator and an excellent teacher. In 1899 he was part of a powerful committee put together to consider adding electrical and mechanical engineering courses to the curriculum. Perhaps due to his background in civil engineering, Alexander was not as active in promoting the addition as some would have liked; however, he was not opposed to it, and under his headship the engineering syllabus was considerably expanded. Affectionately known by his students as ‘Tommy Alexander’, he was a first-rate teacher with a dry sense of humour, and was renowned for being kind and considerate. He taught mostly civil engineering subjects, continuing the work he had started in Japan, and concentrated on structural analysis and design. During this time, he also published several elementary textbooks and, with a grant from the RIA, designed and built an elliptograph that is now held in the engineering school museum. In demonstration of the esteem in which he was held, a ten-course dinner, known as ‘Alexander's feast’, was given at The Hall (later Merrion Hall), Merrion St., to commemorate his twenty-fifth year as departmental head (10 December 1912), many past and present students came from faraway countries to honour him.
While in Dublin, Alexander lived in Sandymount and at TCD, but when he retired (1921) he moved to London, where he continued with his scientific writing. He received several key acknowledgments in his lifetime: an honorary MA from TCD (1888), an honorary doctorate in Japan (1915), and honorary membership of the ICEI (1923). He died 17 February 1933 at his residence at 36 Temple Fortune Hill, London. His memory is kept alive by the Alexander prize, endowed by a fund established by his former pupils and friends, and annually awarded at the BAI degree examination at TCD.