impossible to measure

References in classic literature ?
Then from the bottom of this passage, the depth of which it was impossible to measure, he saw appear, first the head, then the shoulders, and lastly the body of a man, who sprang lightly into his cell.
And Anne, who gave her a second chance at life, said: "It's impossible to measure our friendship.
This is a major problem that makes it almost impossible to measure accurately temperature by optical means if the material surface is non-uniform.
Continued use did improve the appearance and tone of skin, but the promise of improved tolerance is impossible to measure.