'Moment of importance' in Mrs. Dalloway

For having lived in Westminster—how many years now? over twenty—one feels even in the midst of the traffic, or waking at night, Clarissa was positive, a particular hush, or solemnity; an indescribable pause; a suspense (but that might be her heart, affected, they said, by influenza) before Big Ben strikes. There! Out it boomed. First a warning, musical; then the hour, irrevocable. The leaden circles dissolved in the air.

Percy Shelley's Death - 1822

Percy Bysshe Shelley died on July 8th, 1822 at the age of 29. He died off the coast of the Gulf of Spezia, which is on the north-western coast of Italy and in the northern part of the Tyrrhenian Sea. His boat was overturned during a storm that is described as happening suddenly. Shelley and his wife, Mary Shelley, had a house on this Ligurian coast, and Percy was inspired by the views and began a poem called "The Triumph of Life" -- a bit ironic, isn't it?