The owner called the watch incorrigible. (incorrigible: unreformable, uncorrectable, inveterate) To spend another hour on it seemed perverse. (perverse: contrary, obstinate, wayward) Yet the repairer could not divest herself of a suspicion that its faults were connected. (divest: rid, free, disencumber) Each tiny manipulation of the case changed the beat. (manipulation: handling, maneuvering, adjustment) An almost invisible, unyielding ridge pressed on the spring. (unyielding: rigid, hard, inflexible)
The effect was insidious. (insidious: pernicious, treacherous, stealthy) At first the hands lost scarcely an iota of time; a month later their error was impossible to ignore. (iota: jot, trace, tiny amount) Repeated polishing of the face had done nothing to correct it. The repairer lifted the ridge with a blade and listened.
The owner wanted an account of her unprecedented success for his club's gazette. (unprecedented: unheard-of, novel, new) She gave him the essence of it in one sentence. (essence: core, substance, heart) When he closed the case, he had been squeezing the spring.