One of three matching bracket pilaster mounts.  Empire style with pendant tongues decorated with palmetto below a frieze of rosettes.
<div class="fn value">
Unknown artist<span style="display: none;">Unknown artist</span></div>
<a rel="nofollow" class="external text" href="https://collection.cooperhewitt.org/objects/18153071">Catalog</a> <a rel="nofollow" class="external text" href="https://images.collection.cooperhewitt.org/136788_6bfe4b9c1b4fd8ed_x.jpg">Photo</a>