His father, descended from a family of small tenant farmers residing at Coltfield in the parish of Alves in Elgin, became an inspector of masonry under the great engineer, George Stephenson, and was engaged in building the well-known skew bridge near Rainhill at the time of his son's birth.
He was afterwards engaged, under Messrs. Grissel & Peto, in building the new houses of parliament, and fashioned with his own hand much of the stone tracery of the great window at the east end of Westminster Hall.
Within a year he left London and found employment till 1849 under Brassey's agent, Thomas Jones, in the construction of the Harecastle tunnel on the North Staffordshire Railway.
On the completion of this work he undertook the contract for building the principal tunnel entrances, and was for a short time in charge of the construction of the bridges on the Churnet Valley branch of the North Staffordshire Railway between Froghall and Alton.
Before the close of 1849 Brassey appointed him assistant engineer under his agent, Miles Day, in charge of the mining and brickwork of the Walton or Sutton tunnel on the Birkenhead, Lancashire, and Cheshire Railway.
With the concurrence of the North Western board he also accepted the post of manager of the Oswestry, Newtown, and Llanidloes Railways from Thomas Savin, who had leased those lines.
At the prolonged inquiry before the board of trade in 1889 as to the revised schedules of maximum rates and charges preferred by the companies under the railway and canal traffic bill of 1888, he was under examination for eight days, and was highly complimented by the chairman, Lord Balfour of Burleigh, on the quality of his evidence.
On the retirement of Sir Richard Moon in the same year, Findlay was offered the post of chairman of the London and North Western Company, but preferred to retain his more arduous position.
His jocular remark to a committee of the House of Commons that he could manage all the railways in Ireland, and find time for two days' fishing a week, was based on no exaggerated estimate of his own capacity.