““… I said about limiting factors. Well, there’s one that you can’t beat. Put steel under fifty thousand pounds per square inch pressure and it starts to flow. The metal used in this machine must have been able to withstand much greater pressure, but there was a limit beyond which it was not safe to go. At twenty miles above the planet’s surface, they had reached that limit. They had reached dead end.” <…>”
Из малой прозы
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Clifford D. Simak 137
American writer, journalist 1904–1988Related quotes

A dîner, il nous disait qu'il se trouvait beaucoup mieux, et nous lui avons fait observer, à ce sujet, que, depuis quelque temps néanmoins, il ne sortait plus, et travaillat huit, dix, douze heures par jour.
«C'est cela même,» disait-il: «le travail est mon élément; je suis né et construit pour le travail. J'ai connu les limites de mes jambes, j'ai connu les limites de mes yeux; je n'ai jamais pu connaître celles de mon travail.»
Mémorial de Sainte Hélène, Volume 6, p. 272 https://play.google.com/books/reader?id=qSliAAAAcAAJ&printsec=frontcover&output=reader&hl=en&pg=GBS.PA272
About
"Poem" — these lines are among those quoted on the The Pacifist Memorial http://www.peaceabbey.org/memorial/memorial.htm
The Speed of Darkness (1968)
Context: We would try to imagine them, try to find each other,
To construct peace, to make love, to reconcile
Waking with sleeping, ourselves with each other,
Ourselves with ourselves. We would try by any means
To reach the limits of ourselves, to reach beyond ourselves,
To let go the means, to wake.

After the match in which Kohli powers India into the World T20 semi-final, quoted on sports.ndtv, "Virat Kohli Proves His Era Has Begun, After Guiding India Into World T20 Semifinals" http://sports.ndtv.com/icc-world-twenty20-2016/news/256920-virat-kohli-proves-his-era-has-begun-after-guiding-india-into-world-t20-semifinals, March 27, 2016.

Remarks made at the meeting of the German warlords at Advanced General Headquarters at Avesnes (11 August 1918), quoted in John Terraine, To Win A War: 1918 The Year of Victory (London: Cassell, 2003), p. 121
1910s

"Exoticism and Low Life", p. 174.
Music, Ho! (1934)

“When you think you have reached the limits of prestissimo, go twice as fast.”
1948 Today, I should like to ammend this as follows: Go twice as slowly - addressed to conductors of Mozart
Recollections and Reflections