J. Blaylock was a professional oarsmen from Low Elswick, Newcastle-upon-Tyne.
He competed and won the 1877 handicap race at Chester-le-Street.
Also, Bell's Life 28th July 1877 reported:
McDonald v Blaylock for £10
On Thursday night, a somewhat curious open boat race was brought off on the Tyne, from the Redheugh Bridge to the west end of the Tyne Amateur Rowing Club boathouse, a distance of about a quarter of a mile, for £5 a side between J. MacDonald and T. Blaylock (both of Newcastle) the former of whom, who is over 70 years of age, was in receipt of 116 yards start. Both wind and tide were against the competitors when they put off and there was a good deal of ripple upon the surface of the water. Under these circumstances the race was booked a good thing for the young and well-built Blaylock, upon whom two to one was offered, without leading to the transaction of much business. The old man got fully away with the strength of his start, but whatever his own idea may have been, he could not scull any, and Blaylock, dashing along in very good style, rowed up alongside of him at Cooper's Stairs. The young one, however, then slackened considerably, and MacDonald held a lead of a couple of lengths until 100 yards form the goal, when Blaylock spurted past him and won by a length and a half. Robert Bagnall of Ouseburn was the Starter and Referee.