The feature on Brunel (NCE 24 February) forgets that this celebrated name was carried by three generations of civil engineers, and more particularly, that Isambard Kingdom Brunel's father, Sir Marc, was the engineer of the remarkable Thames Tunnel.
You have also upset Robert Stephenson in the spelling of his name.
IK Brunel's research seems to have been a response to his early experiences with cast iron bridges on the main line of the Great Western Railway, rather than paving the way for them.
His collaborator, J Colthurst, described the experiments for determining the position of the neutral axis in an attempt to observe cast iron's non-linear stress-strain behaviour in the Minutes of Proceedings of the ICE, Vol 1 (1841), pp118-123.
Malcolm T Tucker (M), engineering historian and archaeologist, 9 Blythwood Road, London, N4 4FU