In 1806, they took a first step by hiring Ferdinand Hassler. Hassler, a Swiss mathematician and geodetic surveyor who was noted for his work on a topographic survey of Switzerland, had immigrated to Philadelphia in 1805, two years after the French invaded his country and made his work there impossible. Through the auspices of a merchant friend with friends in New York, in the spring of 1806, the Common Council commissioned Hassler to make an accurate map of Manhattan Island, which could be used as a basis for planning future development; it would be Hassler's first substantial contract in the U.S. He accepted the job, and the terms: $5 per day for Hassler (), $4 dollars a day for his assistant (), and $1 per day for expenses (), plus a budget sufficient to hire a surveying crew. He was scheduled to depart from Philadelphia in July, in time for at least part of the 1806 surveying season, but never appeared. Finally, in October, he sent his regrets: both he and his wife had taken ill on the day they intended to leave. Why they didn't send word earlier, why Hassler didn't press on at some point before October, and why the Common Council never thought to inquire of the whereabouts of their missing surveyor is not known. In any case, by October, the surveying season for 1806 was over, or close to it. Hassler soon received a federal appointmenthe would eventually head the first Coast Surveyso the Council was back at square one.