 He prepared estimates for bids for various concerns on extensive improvements, such as the Atlantic Branch of the Long Island Railroad; the portion of the New York City Subway's IRT Lexington Avenue Line/IRT Eastern Parkway Line from Brooklyn Bridge – City Hall station at New York City Hall to Atlantic Avenue station at Flatbush Avenue, Brooklyn, including the Joralemon Street Tunnel under the East River; and finally, the track elevation of the New York Central Railroad at Schenectady, New York; and assisted in the examination of the new filtration plants, pumping stations, and aqueduct tunnel of the Philadelphia Water-Works.Many other services were performed by Cattell while he was engaged in the practice of his profession as Consulting Engineer in New York City, and the foregoing only illustrates the nature and scope of his work up to the time that he became associated with the firm of E. H. Rollins and Sons, of San Francisco, California, which firm he served as Consulting Engineer from 1905 to 1908, making examinations and reports, for bond purposes, on various steam and electric railroads, among the latter being the Western Pacific Railroad.It was during these years that he served as President of the Petaluma and Santa Rosa Electric Railway.