The following Autobiography was written by Sir John Rennie in 1867, shortly after he had retired from the active duties of his profession. As will be perceived in the sequel, it was composed wholly from memory. Sir John was subsequently unable to revise it as he would have desired, and it has since been found impossible to do so. Nevertheless it is believed that but few substantial errors will be found; while the kindliness with which the autobiographer invariably speaks of every person with whom he came in contact, is a guarantee that there can be nothing to offend the most sensitive person, or which might tend to injure the just claims and reputations of others. It is now presented to the public in its original state, having undergone merely some necessary correction, in the hope that the memoirs of the man who was perhaps unrivalled in his branch of the profession—and which comprise valuable hints as to the neglected art of hydraulics, as well as advice to engineers commencing their career, the result of the experience of a lifetime of no ordinary duration—together with the reminiscences of one who had seen much both of men and things,

may not be unacceptable either to the profession or the world at large.

London, September, 1875.