Down, February 9th [1865].
I quite agree how humiliating the slow progress of man is, but every one has his own pet horror, and this slow progress or even personal annihilation sinks in my mind into insignificance compared with the idea or rather I presume certainty of the sun some day cooling and we all freezing.

To think of the progress of millions of years, with every continent swarming with good and enlightened men, all ending in this, and with probably no fresh start until this our planetary system has been again converted into red-hot gas.

Sic transit gloria mundi, with a vengeance...
LETTER 186.

TO B.D.WALSH.

Down, March 27th [1865].
I have been much interested by your letter.