1870-1920. Electric light, automobiles, aircraft, radio, paved roads. Railroads everywhere in the developed world.  Electric mass transit (trolleys, subways) in major cities.  Tractors and combine harvesters on farms.  Refrigeration. X-rays.<p>In computing, the Computing-Tabulating-Recording company (later IBM) produced the first printing tabulator, the beginning of commercial data processing.<p>Those 50 years held the greatest lifestyle changes in history.