[1] From 1832 he spent six years working as an engineer in Constantinople, Ottoman Empire, helping build an ordnance factory on behalf of machine tool manufacturers Maudslay, Sons & Field.

[1] Barlow returned to Britain in 1838 to take up a post as assistant engineer on the Manchester and Birmingham Railway working for George W. Buck.

It had a wide flanged profile which could be laid directly on to track ballast without the need for sleepers, with just periodic tie-bars to maintain the correct gauge.

[1] Joseph Paxton, designer of the cast iron and glass Crystal Palace for The Great Exhibition of 1851, was a director of the Midland Railway and he asked Barlow for his help in the preparation of the structural calculations for the frame of the building.

[1] Following the death of Isambard Kingdom Brunel in 1859, Barlow was commissioned with John Hawkshaw to complete the Clifton Suspension Bridge, Bristol, construction of which had been stalled since 1843 due to insufficient funds to finish it.

To deal with the sloping site and the need to cross the Regent's Canal a short distance to the north, the platforms were constructed on a raised structure supported on cast iron columns and girders.

[5] With assistance from Rowland Mason Ordish,[6] Barlow also designed the arched, cast iron station canopy which spans 240 feet (73 m) across the platforms without intermediate support – then the widest of its kind in the world.

As the newly elected President of the Institution of Civil Engineers,[note 3] Barlow was appointed as a member of the Board of Trade's Court of Inquiry into the disaster.

[1] In 1881 Barlow sat as member of the Wind Pressure (Railway Structures) Commission established at the recommendation of the Tay Bridge report.

From 1873 he was a member of a Board of Trade committee which produced the first recommendations on safe working loads for steel in railway structures in 1877.

In February 1874 he presented the Royal Society with a talk On the Pneumatic Action which accompanies the Articulation of Sounds by the Human Voice, as exhibited by a Recording Instrument.

He served as Vice President of the Royal Society in 1881 and was an honorary member of the Société des Ingénieurs Civil de France.