Astrocompass, Mark II, "Excalibur III". Creator: W. W. Boes Co..
2-839-981 - Heritage Art/Heritage Images
Aluminum with black enamel finish. Approx. 4" dia. x 12" high. Used in polar navigation. Nameplate on the base reads "ASTRO-COMPASS MK II / The W.W. BOES CO. / DAYTON, OHOIO, USA