Clifford Milburn Holland was born in Somerset, Massachusetts on March 13, 1883. He graduated at Harvard University in 1905 and received from that institution the degree of S.B. in Civil Engineering in 1906. He began his professional career in New York City as assistant engineer of the Joralemon Street tunnel under the East River, and was connected with that work until its completion in 1909. Then he was employed by the Public Service Commission as an assistant engineer (1912-1915), division engineer (1915-1919), and tunnel engineer (1919-1924). In the latter capacity he had charge of all tunnels being built under the East River in New York City. In 1919 he was appointed chief engineer of the New York State Bridge and Tunnel Commission and the New Jersey Interstate Bridge and Tunnel Commission with the charge of designing and constructing the vehicular tunnel under the Hudson River begun in 1922. Now known as the Holland Tunnel, this work was the first of its kind for vehicular use and offered a number of unusual problems which taxed his ingenuity and skill to the utmost. Among these problems were the proper ventilation of the tunnel and the removal of the deadly carbon monoxide gas generated by automobile engines. This was achieved by providing a pure air chamber at the bottom of the tunnel fed by seven air shafts, and a foul air chamber at the top, with air pumps to keep the air constantly changing. The tunnel is 9250 ft. long and large enough to accommodate two lines of vehicles to the number of 46,000 daily. In boring the portion under the river (5,480 ft.) Holland used six gigantic shields, each weighing 400 tons, which were set to work at the New York and New Jersey terminals and by means of powerful jacks propelled by hydraulic pressure. The shields bored their way toward one another through silt, earth, and rock, until they met twenty-five feet below the bed of the river at almost exactly the same spot. The tremendous labors and responsibilities attending the work caused Holland a nervous breakdown from which he did not recover. Clifford M. Holland died at Battle Creek, Michigan, on October 27, 1924.