John Roe (1795-1874)
1842 John Roe of Clerkenwell, Surveyor of Sewers in the Holburn and Finsbury District, became a member of the Institution of Civil Engineers.
1875 Obituary 
John Roe was born at Ashbourne, in Derbyshire, on the 24th of July, 1895.
He was educated at Skipton, Uffington, and Wantage Academy.
As a contractor he carried out numerous works, both public and private; among them a railway from Moreton-in-the-Marsh to Stratford-upon-Avon in 1826, also a road near Long Compton in 1827.
In the year 1830 he was appointed surveyor to the Holborn and Finsbury Commissioners of Sewers, an office he held until the commission was superseded. He eventually became Surveyor-in- Chief to the Metropolitan Commissioners of Sewers, and finally retired from that office on a pension.
During his term of office he carried out a series of important and valuable improvements in relation to drainage. After making a number of observations, and ascertaining by measurement the proportion of liquid to solid sewage, also the quantity of sewage matter carried off by the sewage stream in suspension, he established the present practice of cleansing sewers by flushing, and abolished the obnoxious system of opening the sewers and lifting the sewage by windlass and bucket. Then followed the construction of egg-shaped sewers in lieu of flat-bottomed sewers and semicircular bottomed sewers, also of side entrances, improved gully drains, and house drains.
Mr. Roe introduced the system of pipe drains, and expended much time for many years in ascertaining the effect of rainfall upon the sewage streams within the sewers. Night and day, for a long period, the sewage and rainfall of a given area were measured, the rainfall gauged, and the loss by absorption in different soils and by evaporation ascertained.
The plan of emptying by the night-cart gave way to that of removal by pumping, after disinfection and dilution, direct into the sewers; and eventually the cesspools, to a large extent, were abolished, and the present prevailing system of water-closet established.
A series of experiments were also carried out on the quantity and velocity of water flowing through pipes of different diameters and varying falls. The results of some of Mr. Roe's investigations were embodied in the tables published by the General Board of Health, in 1852 and subsequent years, in their Minutes of Information for Local Boards of Health.
Mr. Roe also designed a scheme for the Northern drainage of London, and his Report thereon was presented to the Metropolitan Commissioners of Sewers on the 23rd of October, 1864.
In 1850 Mr. Roe was appointed to carry out the drainage of Windsor. His advice was also obtained for the drainage of Eton, Eton College, Derby, Beaconsfield, Reading, Harrow-on-the-Hill, and other places. In the drainage of Harrow the outfall pipe was 18 inches in diameter only.
Mr. Roe was elected an Associate of the Institution on the 1st of February, 1842, and on the 19th of the same month contributed a Paper 'On the Causes of Accumulation of Deposit in Sewers,' in which the usual mode of removing that deposit was alluded to, and a description was given of a flushing apparatus for cleansing sewers. He died on the 15th of March, 1874, aged seventy-nine years.