Unknown Tool

Ok, so the two clamps go on the battery or power source (I wish it had another nameplate with ratings on it) and then the two probes likely drive the "globe" which I assume is a vacuum tube, probably cathode-ray. It could possibly detect voltage signals between probes similar to a Oscilliscope but very low tech.

So my bet is it is a very old version of a high voltage wire tester (like a spark plug wire tester very early)

RGAZ