Parliament, after an inquiry by Select Committee, passed the "Metropolitan Commons Act"[108] in 1866, which prescribed a mode of procedure under which the commons in the neighbourhood of London could be permanently procured for the people of London, and the Metropolitan Board set to work to procure them. The acquisition of Hampstead Heath was happily arranged in 1870. Another great work was also undertaken by the Central Authority--namely, the embankment of the Thames. The offensive state of the river had been greatly enhanced by the large areas left dry at low water on which sewage matter collected and putrefied; and the only way of removing this cause of mischief was by confining the current within a narrower channel. Parliament passed an Act in 1863, entrusting its execution to the Metropolitan Board, and the work was soon after commenced. Thus in these matters, all of which were closely associated with the public health, the sanitary evolution of London was progressing, and the Board was giving visible demonstration of the necessity of that which had so long been denied to London--namely, a central governing authority to deal with matters affecting London as a whole. The Board, in their report for 1865-6, stated they were: "Deeply sensible of what remained to be done to remedy the neglect of past ages, and to render the metropolis worthy of its position as the chief city of the Empire;" but they were hampered by the want of means to enable them to carry out desired improvements. "It cannot be questioned," they wrote, "that direct taxation now falls very heavily upon the occupiers of property in the metropolis.... It appears to the Board that the most equitable and practicable mode of raising the necessary funds would be by imposing a portion of the burden on the owners of property. It cannot be denied that the interest of the latter in metropolitan improvements is much greater than that of temporary occupiers, and yet at the present time, the occupiers of property in the metropolis bear almost the whole cost of the improvements effected by the Board. It is hoped that the representations made by the Board will satisfy the Legislature of the injustice of the present state of things, and lead to some equitable remedy." The visitation of cholera was doubtless in the main accountable for the excess of energy displayed by Parliament about this period in matters affecting the public health. In the same session that the Sanitary Act was passed, a measure of considerable importance to the consumers of water in London was passed, though many years would elapse before its effect would be appreciable. This was "The Thames Purification Act."