Prior to these amendments of the Act 1868, it was felt that it dealt only with isolated buildings, and consequently, in order to improve large areas, the “Act for Facilitating the Improvement of the Dwellings of the Working Classes in Large Towns” was passed in 1875 (38 & 39 Vic. c. 36), since which date, like the Act 1868, it has been twice amended, once in 1879 (42 & 43 Vic. c. 63), and again in 1882 (45 & 46 Vic. c. 54). The object of the Act of 1875 was to facilitate the removal of portions of towns, especially of the courts and alleys in the poorer and more densely-populated parts. The Act is to be put in force where an official representation is made by the medical officer of health to the local authority of an urban sanitary district (which must contain a population of at least 25,000) that “any houses, courts, or alleys within a certain area” are “unfit for human habitation, or that diseases indicating a generally low condition of health amongst the population have been from time to time prevalent in a certain area,” and that this is attributable to the bad arrangement or bad condition of the streets and houses, or “other sanitary defects,” which can only be remedied by “an improvement scheme for the rearrangement and reconstruction of the streets or houses” (38 & 39 Vic. c. 36, s. 3). The improvement scheme to be prepared on receipt of this report by the local authority must be accompanied by “maps, particulars, and estimates” (no doubt these must be prepared by the surveyor, although no mention is made as to who shall prepare them), and this scheme may “provide for widening any existing approaches to the unhealthy area, or otherwise for opening out the same for the purposes of ventilation or health.” It must distinguish “the lands proposed to be taken compulsorily,” and by the Act 1875 it was necessary to “provide for the accommodation of at the least as many persons of the working class as may be displaced in the area with respect to which the scheme is proposed in suitable dwellings, which, unless there are any special reasons to the contrary, shall be situate within the limits of the same area or in the vicinity thereof” (sec. 5). So much practical difficulty was experienced in carrying this latter part of the clause into effect, that in 1879 a short Act was passed (42 & 43 Vic. c. 63), which by the 4th section amended that part of the original clause as to the provision of accommodation for the working classes as follows: