Excerpts of the President's News Conference
The condition of my father seems to be about the same. I suppose he is gradually growing weaker. There doesn't appear to be any noticeable change. Some days he is a little stronger and brighter and takes more nourishment, and other days he seems to be weaker and doesn't take much nourishment and doesn't converse much with anyone unless they speak to him.
Source: "The Talkative President: The Off-the-Record Press Conferences of Calvin Coolidge". eds. Howard H. Quint & Robert H. Ferrell. The University Massachusetts Press. 1964.
Calvin Coolidge, Excerpts of the President's News Conference Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/349144