This Ventometer, labeled as a large bore anemometer, is an intricate and precise tool designed for measuring windage or airflow, particularly in large bore applications. Manufactured by W.J. Jeffery & Co., Gun & Rifle Makers, it features a detailed scale and adjustments for precise readings. The tool's build quality and design indicate use in firearms-related settings, possibly for ballistic or environmental wind adjustments. It is in good condition with clear engravings and functional components. For Martini Henri and Enfield rifles
