I think this is most likely Harry Eltherbert Dawson. According to his attestation papers dated July 31, 1915, Harry Ethelbert Dawson was born in Toronto on July 12, 1894. He listed his father, Harry Dawson, 231 Lansdowne Avenue, Toronto as his next of kin. He was a saddler and was an active member of a militia. He was 21 years of age and stood 6 feet tall. He had brown eyes, brown hair and a dark complexion. He was a member of the Church of England.
He is listed on the Honour Roll and cenotaph as being killed but I cannot find a record of his death.