1909 Scientific American  
Some great records for steam shovel work are being made on the Panama Canal. Recently, during a work ing day of eight hours a steam shovel, operating in the Empire Construction District, removed 3,941 cubic yards of rock and earth. The sbove!" was actually at work only six hours and fifty minutes of this time,
doi:10.1038/scientificamerican04241909-311a fatcat:ifo3dwguknbcbewrewhcg26clu