Of still deeper interest and import was the information obtained as to that dreadful factor in London life--"overcrowding." An effort was now for the first time made to get reliable information upon this matter. Hitherto it was only by piecing together the statements made by some of the Medical Officers of Health as to overcrowding in their respective parishes that one could form even the crudest idea of what the sum total in London actually amounted to. Here, at last, was material enabling accurate calculations to be made, not only of overcrowding in each separate parish or district, but in London as a whole. The Census Commissioners laid down the principle-- "That ordinary tenements which have more than two occupants per room, bedrooms and sitting-rooms included, may be considered as unduly overcrowded. "We may," they wrote, "be tolerably certain that the rooms in tenements with less than five rooms will not in any but exceptional cases be of large size, and that ordinary tenements which have more than two occupants per room, bedrooms and sitting-rooms included, may safely be considered as unduly overcrowded." By using the information given in the tables, and excluding all one-roomed tenements with not more than two occupants, all two-roomed tenements with not more than four occupants, all three-roomed tenements with not more than six, and all four-roomed tenements with not more than eight occupants, the desired information would be obtained. And they added:-- "Each Sanitary Authority is now provided with the means of examining with much precision into the house accommodation of its district." Provided with the tables as to the occupants of tenements, the Medical Officer of Health for the London County Council, in his report for 1891, worked out the figures for the metropolis. The result showed that there were in London 145,513 tenements of less than five rooms apiece, in each of which there were more than two inhabitants per room, and each of which consequently was "overcrowded." But it is when one ascertains the number of persons living in these overcrowded tenements that one realises what the extent of overcrowding was. In round numbers, one-fifth of the entire population of London lived in these tenements. The total population was 4,200,000; the number of "overcrowded" persons was 830,000. A few illustrations of the overcrowding in certain parishes brings the meaning of these figures home still more. In Clerkenwell, 25,600 persons lived in overcrowded tenements; in St. Luke, 18,700 persons; in Shoreditch, 41,700; in Islington, 64,600; in Kensington, 28,700; in Lambeth, 43,600. The larger proportion of these lived in one- or two-room tenements.