which year did its sculpting first begin?
May 1915
Fountain of Time
 Taft first created a quarter-scale model which received the Trustees' approval in May 1915. 
what is fountain of time? It  is a sculpture by Lorado Taft where can you find that piece of work? In the Washington Park community area on Chicago's South Side
wiki:8588133
Fountain of Time [SEP] Planning
This would enable the model to be evaluated in 1918. Taft first created a quarter-scale model which received the Trustees' approval in May 1915. He eventually produced his full-scale plaster model, in width peaking in the center, with an equestrian warrior and a robed model of Father Time with a height of . The installation of this model near its intended location was delayed by Taft's World War I service with the Y.M.C.A. in France as part of a corps of entertainers and lecturers, but was completed in 1920. However, Taft's wider vision of a Chicago school of sculpture, analogous to other philosophical Chicago schools such as the contemporaneous Chicago school of architecture style, had lost momentum after the 1913 dedication of his "Fountain of the Great Lakes".