Hobkirk was born in Edinburgh, and from 1897 is found to have given St Ives as his exhibition address. Tovey relates some details about his mother, Baroness Farina Firras, and a younger brother who were staying in the town until about 1904, primarily at the Hendra Hotel, and the 1901 Census references him as living with his wife at 4 Albany Terrace.

He was among the members of the St Ives Arts Club to sign the 1898 Glanville letter (regarding artists' concern at over-development and proposed building work in the town). By 1920 his address was given as Tonbridge, Kent, although his studio in St Ives was still attracting rates in his name until 1917 and he is not thought to have been present after 1904.

Paris Flower Market (under the awnings); Garlic Blossom and St Ives Bay were the titles exhibited by this artist at the Whitechapel Exhibition in 1902. He exhibited widely, if not prolifically, elsewhere (J&G list).