<P> Conditions improved over the course of the 19th century due to new public health acts regulating things such as sewage, hygiene and home construction . In the introduction of his 1892 edition, Engels notes that most of the conditions he wrote about in 1844 had been greatly improved . For example, the Public Health Act 1875 led to the more sanitary byelaw terraced house . </P> <P> In The Condition of the Working Class in England in 1844 Friedrich Engels described how untreated sewage created awful odors and turned the rivers green in industrial cities . </P> <P> In 1854 John Snow traced a cholera outbreak in Soho to fecal contamination of a public water well by a home cesspit. Snow's findings that cholera could be spread by contaminated water took some years to be accepted, but his work led to fundamental changes in the design of public water and waste systems . </P> <P> Pre-industrial water supply relied on gravity systems and pumping of water was done by water wheels . Pipes were typically made of wood . Steam powered pumps and iron pipes allowed the widespread piping of water to horse watering troughs and households . </P>

The american revolution was driven in large part by