At either end of the scale are notes that stir no chord of that imperfect instrument, the human ear.

Even today, "universities use imperfect instruments called 'exams' to indirectly quantify something they call knowledge."

The human eye is an imperfect instrument; its range is but a few octaves of the real "chromatic scale."

The Church's collective memory was an imperfect instrument.

For Wells, the adaptation of the "very imperfect instrument" of the human mind to new and developing possibilities is the essence of humanity's economic problem.

Winthrop's telescope must have been specially good for him to see this faint object with his imperfect instrument in 1664.

But why, Mother of all, do you send me to do your will with imperfect instruments?

The human race is at a disadvantage because of their imperfect instruments and cannot know what the invisible beast, or what any animal in nature, will do next.

"People are imperfect instruments, but they must be coordinated for the greater good, even the pompous buffoons."

And yet, how was this granite wall to be opened without powder, and with imperfect instruments?