Kurma: The devotees had set up two bells in Prabhupada's room. A wind-up bell, more like a buzzer and operated by pressing a button, was for Prabhupada to call Srutakirti to his room. A small brass hand bell sitting on Prabhupada's desk was rung by Prabhupada whenever he wanted to speak to Paramahamsa Swami.
Ganesa: It was about 4 a.m. I had taken my early morning bath under the tap in the front garden. Srutakirti and the others were splashing and diving in the pool. Prabhupada's door was open, and although I didn't know it at the time, my chanting in the lounge adjoining Prabhupada's room, although very soft, was distracting Srila Prabhupada from his writing. I heard the buzzer. "That's the servant's bell," I thought. "It's for Srutakirti."
I anxiously glanced out of the window to see Srutakirti swimming backstroke in the pool. "Srutakirti had better get in here soon because Prabhupada wants him," I thought. Again the buzzer sounded. I peered nervously and saw Srutakirti, now swimming free-style. "If he doesn't come now, Prabhupada's going to be really angry." The buzzer sounded longer and more insistently.
Confused, I ran into Prabhupada's room and quickly offered my obeisances. "Prabhupada, Srutakirti's still taking bath," I blurted, "and..." "That's all right," Prabhupada yelled, "One who hears this bell must come!" He added softly, "Please shut the door."
I left the room having learnt two good lessons: Srila Prabhupada deserved the best possible arrangements for peaceful writing. Our chanting was for our benefit, but Prabhupada's books were meant for the benefit of all humanity for thousands of years to come. I also realized that I was also Prabhupada's servant, not just Srutakirti.
Reference:The Great Transcendental Adventure - Kurma Dasa