A ship’s telegraph was used to transmit engine orders from the wheelhouse to the machinery spaces. Unfortunately the wheelhouse and engine room telegraphs on the Explorer have been purloined leaving only the stokehold instrument. The wheelhouse would use a handle to position the telegraph to order the desired speed. A bell would ring in the machinery spaces and continue ringing until the order was responded to by the engineer. The stokehold instrument is only a repeater so no response is possible. The duty fireman would use the order to decide whether to increase or decrease the firing of the boiler.