Captain Cordell William Firebrace (1865-1934) was born in Australia and moved to England where he joined the 7th Hussars. He eventually became a JP, and was elected a Fellow of the Society of Antiquaries in 1930. He returned to Australia after his father's death in 1903 to take up an inheritance but continued to spend time in England at Elmstone Court in Kent where he built a grotto in 1909. He was related to Sir Henry Firebrace (1619-1691) who had a crest granted in 1677. It was revived in 1911 to adorn this bookplate, presumably. The plant on the left is a tree fern and on the right, an oak.
Bookplate (click to enlarge)