(b. 1700, Nancy, d. 1759, Nancy)
French sculptor belonging to a family of sculptors. Originally from Lorraine, the earliest known members of the family to be involved with the arts were Sigisbert Adam, a sculptor, and Lambert Adam, a metal-founder (both active late 17th century). Lambert's son Jacob-Sigisbert Adam spent most of his working life in Nancy, where he undertook the early training of his sons Lambert-Sigisbert Adam (1700-1759), Nicolas-Sébastien Adam (1705-1778), and François-Gaspard-Balthazar Adam (1710-1761). His daughter Anne married Thomas Michel (d. before 1751), a sculptor from Metz; among their children were the sculptors Sigisbert-François Michel (1727-after 1785) and Claude Michel (known as Clodion). The three Adam brothers went to Rome at the start of their careers, Lambert-Sigisbert and Nicolas-Sébastien returning to France to work on the outdoor sculpture at Versailles, among other projects, and François-Gaspard-Balthazar going on to Sanssouci, Potsdam.
Lambert-Sigisbert was the most distinguished member of the family. He was a pupil of his father and finished his training in the Paris workshop of François Dumont. In 1723 he won the Prix de Rome. During his period in Rome, at the Académie de France, he was patronized by the influential Cardinal Melchior de Polignac, the French Ambassador to the Holy See, for whom he restored and copied antique sculpture. He contributed a relief of the Virgin Appearing to St Andrew Corsini to Clement XII's Corsini Chapel at S Giovanni in Laterano (marble, c. 1732) and became a member of the Accademia di S Luca, presenting a bust of Sorrow (marble, 1732). He also entered the competition for the Trevi Fountain, but although his elaborate Baroque design (1731) was selected as the winner, Clement XII eventually commissioned the fountain from Nicola Salvi.
He returned to Paris in 1733 and produced reclining statues personifying The Seine and The Marne rivers for the cascade at Saint-Cloud (1733-4). He was received into the Academy in 1737. His masterpiece, sculpted in collaboration with his brother Nicolas-Sébastien, is the Neptune Fountain (1740) at Versailles, a work showing the influence of Bernini in its exuberant movement. He also published in 1754 a collection of Greek and Roman sculpture.