He was the son of a Hudson's Bay Company fur trading factor and was among the first graduates of the Queen's University electrical engineering program in 1898.

On graduation Fortescue joined the Westinghouse Corporation at East Pittsburgh, Pennsylvania, where he spent his entire professional career.

Also in that year he was one of the authors of a paper on measurement of high voltage by the breakdown of a gap between two conductive spheres, which is a technique still used in high-voltage laboratories today.

[3] He was awarded the Franklin Institute's 1932 Elliott Cresson Medal for his contributions to the field of electrical engineering.

[4] Fortescue obtained 185 patents in his career, in the design of transformers, insulators, and DC and AC power circuits.