Interesting to see the modularization of that panel so early in the game. Very logical. Each module with a tube inside has associated jacks so that a meter box can be used to quickly check operating conditions.

The PA idea makes sense considering the connections for "long line" and "phonograph." Four tubes that size might realize a 1000-watt system.

That appears to be an old public address system with the capability to attach and simulcast over the "long lines" of the phone system. "Loud Speaking Receivers" would be bullhorns. Both consoles are nearly identical. Each console has four tubes with inputs to drive 1&2 and 3&4 separately.

This appears to be a system operator position, and not the position one would speak from. A microphone and a headset earpiece are between the consoles and are connected to the small box between them, not to either console. If I'm right, then the mic and headset would be to coordinate with the other half of this contraption -- probably near the speaker position and/or the other side of that "phonograph circuit."

So why is there a "Phonograph cct"?

Watch out for the carbon tetrachloride fire extinguisher; it's poisonous.

I'm just amazed at the number of porcelain-based knife switches that were used in the operation of the equipment. In looking closer you can see quarter-inch jack plugs, commonly called "phone" jacks. Which went on to become the standard for broadcast patch panels and guitar amplifiers and cables.

in the amplifiers probably had 700 volts on their plate circuits.
My father's first ham (amateur radio) license was issued to him in 1919 and I remember components in our home that looked similar to those pictured.

Click to enlarge. Then click the resulting image to expand it.

Shocking, isn't it?

Of course it wouldn't be complete without a cuspidor.

A fire extinguisher, and what seems to be a cuspidor. Furniture by Flintstone and Rubble.

Looks like a temp facility in the same general location as this..

https://www.shorpy.com/node/5384

Maybe under the East Front? The columns give it away..

Fascinating glimpse onto transitional technology. I wonder if a higher resolution scan would allow the label to be read and some of the functions determined?

Lots of selector switches, several knife switches (looking like telegraph keys), some mics and one big honking speaker. And some lovely woodwork!

Very hi-tech stuff I'm sure, with the obligatory spittoon.