De Prony died in 1839 and his position at the Bureau des Longitudes became vacant. Cauchy was strongly supported by Biot and Arago but Poisson strongly opposed him. Cauchy was elected but, after refusing to swear the oath, was not appointed and could not attend meetings or receive a salary.
Mula Prony namatay sa 1839 at ang kanyang posisyon at ang Bureau des Longitudes ay naging laman. Cauchy ay Matindi ang suportado ng Biot at Arago ngunit Poisson Matindi ang laban sa kanya. Cauchy ay elected ngunit, pagkatapos refusing sa sumumpa ng panunumpa, ay hindi hihirangin at hindi dumalo sa mga pulong o tumanggap ng suweldo.