The main task that Peirce carried out in his geodetic work for the U.S. Coast Survey was to measure the force of gravity at various sites both in the United States and abroad.
Ang pangunahing gawain na Peirce natupad sa kanyang geodetic trabaho para sa US Coast Survey ay upang masukat ang lakas ng gravity at iba't-ibang mga sites na pareho sa Pilipinas at sa ibang bansa.