The modified Mercalli Scale is a means of measuring the intesity of an earthquake. Unlike the Richter scale, which uses mathematical calculation to measure seismic waves, the modified Mercalli Scale uses the effects of an earthquake on the people and structures in a given area to determine its intensity. It was invented by Guiseppe Mercalli (1850–1914) in 1902 and modified by Harry Wood (1879–1958) and Frank Neumann in the 1930s to take into consideration such modern inventions as the automobile and the skyscraper.