The telegraphs are the yellow and red buttons - one set for each engine. The black levers in the middle are called Combinators - these control the engine speed and the pitch of the propellor Blade at the same time these are only used when the engines are on engine room control and not on bridge control. The brass levers are the engine air start.

Also what some people might like to know is the square box on the other side of the control room puts a six volt electric charge through the underwater part of the hull. This will stop barnacles clinging to the ships bottom which gradually slows the ship down in time.

Combinators! That's the word I was thinking of. I seem to recall the same red and yellow telegraph buttons up on the bridge, but in the bridge wings were sets of more conventional level type telegraphs.