William Thomson, 1st Baron Kelvin Quote

To live among friends is the primary essential of happiness.

Lord Kelvin's Replies to Addresses given on the Celebration of the Jubilee of his Professorship (June 15-17, 1896). Quoted in Lord Kelvin, Professor of Natural Philosophy in the University of Glasgow 1846-1899 (1899) by George F. Fitzgerald

Lord Kelvin, professor of natural philosophy in the University of Glasgow 1846-1899, with and essay on his scientific work by George F. Fitzgerald...and an account of the celebrations on the occasion of Lord Kelvin's jubilee as a professor[babel.hathitrust.org]