portholes

Good evening, I recently read an article from 1911 that talks about the ventilation on the titanic, we talk about portholes with automatic ventilation. Can anyone tell me more? In the porthole in the photo there are two "valves" above, does anyone know what they are for...

Hello, how different are the portholes of the 1908 D design, I ask because I'm tempted to do it using a Titanic model. I'm guessing it's quite different from the real ships since the cabins didn't had the corridors with portholes. source: Original General Arrangement plan (1908) -...

Hi everyone, If you were a First class passenger, would you have had to open your own porthole for fresh air? Or would some passengers expect a steward/stewardess to do this for them? I can imagine this possibly happening in the stateroom suites but would it have been too much of an ask if...