Frédéric became a civil servant in 1844, taking a drafting position with the Board of Works, working as an assistant to Frederick Preston Rubidge. He was to be in public works for 46 years. He quickly became a land surveyor and took on translation responsibilities. He wrote extensively for this position, compiling important details of public works history.
As his engineering career progressed he was involved in numerous and diverse public works projects including a number designed by his brother, Charles.
His career is a testament to his technical expertise and the importance of public works in building the prosperity of the country during that era.