NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: USS Arizona mystery superstructure detail
From: Frank Reed
Date: 2016 Dec 8, 17:48 -0800
From: Frank Reed
Date: 2016 Dec 8, 17:48 -0800
That dial was apparently called a "range clock". There are good descriptions here:
http://sci.military.naval.narkive.com/WT9HK41a/that-clock-like-thing-on-the-mast-of-the-arizona.
Frank Reed