The DC motor was the mainstay of electric traction drives on both electric and diesel-electric locomotives, street-cars/trams and diesel electric drilling rigs for many years. The introduction of DC motors and an electrical grid system to run machinery starting in the 1870s started a new second Industrial Revolution.
One acre is 43,560 sq ft. One half acre is 21,780 sq ft. However, that doesn't help most people much when trying to picture how large a lot is. Half acre lot is roughly:
For residents of other countries, the acre might be envisaged as approximately half of a 105 metres (344.49 feet) long by 68 metres (223.10 feet) wide association football (soccer) pitch. It may also be remembered as 44,000 square feet, less 1%.