Illustrated Companion to the Latin Dictionary/Arbusculae

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich. 

ARBUS'CULAE (ἁμαξόποδες). Strong wooden collars, or rings fastened underneath a cart (plaustrum) or under an engine of war, for the purpose of receiving the axle, which revolved together with its wheels in these collars, in the same manner as now seen in a child's go-cart (Vitruv. x. 14. 1. Ginzrot, Wagen und Fahrwerke, i. 91. 3.). When the wheels revolved upon their axle, as was usual for carriages (currus), the axle was of course a fixture, and arbusculae were not necessary.