“An Abraham Lincoln keyed to base uses…”

Just came across this bit of description in a Sherlock Holmes story today, and loved it:

As I looked upon him I understood not only the fears and dislike of his manager but also the execrations which so many business rivals have heaped upon his head. If I were a sculptor and desired to idealize the successful man of affairs, iron of nerve and leathery of conscience, I should choose Mr. Neil Gibson as my model. His tall, gaunt, craggy figure had a suggestion of hunger and rapacity. An Abraham Lincoln keyed to base uses instead of high ones would give some idea of the man.

The Problem at Thor Bridge, Arthur Conan Doyle