Horsepower equipment in the united states, 1869-1929

The merits and faults of the horsepower equipment index as an index of machinery insstallation ar reviewed. Certain defects in horsepower statistics are pointed out. The growth in total horsepower capacity of prime movers is shown by decades from 1869 to 1929, for the country as a whole and for manufactures, mines and quarries, agricoltoure , irrigation and drainage, eletric central stations, eletric railroads, steam railroads, ship, productive and pleasure antomobilies, commercial aircraft, and work animals not on farms. Total horsepower of equipement operated by owned and purchased power is also shown for each field. The various fields are grouped in major classes- materials, manufactred prodcts, and heavy and light trasportation- and the horsepower totals of each are comapred over sxty-years period. The percentage distibutions and relative growths of the different types of prime mover equipment- steam, international cobustion, water, wind, work animals, and purchased-electricity- are given by decades. Certain uses of the horsepower index are suggested.