The training took three afternoons in the workshop, and Copper proved a faster learner than Samuel had expected.
The principle was straightforward: Samuel needed a second set of reliable eyes at close range during the final calibration phase of the clock repair. Copper could not read a seconds dial, but he could be taught to respond to a simple sound — the click of a pen on the workbench — and fetch a specific small object: the brass calibration key that Samuel used to make fine pendulum length adjustments.
This was the foundation of the working system Samuel had in mind, and it was a foundation that Copper already half-understood, because the spaniel had spent four years watching Samuel reach for specific tools from the rack on the workshop wall.
The harder part was the second element. Samuel needed to know if the clock's escapement beat was even or uneven. The beat was audible — the classic tick-tock of a well-regulated anchor escapement — but it was also visual. An experienced clockmaker could watch the escape wheel's rotation and see immediately if the impulse faces were engaging symmetrically or if one side was grabbing earlier than the other.
Samuel's peripheral vision was sufficient to track the large escape wheel of the tower clock, but the critical measurement — the difference in drop angle between the two pallets — required his eye to be positioned within eight inches of the pallet surface.
The solution came from an unexpected direction.
On the second afternoon of training, Copper did something that had not been planned. Samuel had set up a small practice arrangement on the workbench: a dismantled carriage clock movement clamped to a wooden block, with the anchor escapement in view.
He had been explaining, mostly to himself, the problem of what he needed to see when Copper placed his own chin on the workbench beside the clock movement and looked at it.
Not at Samuel. At the movement.
The dog's eyes were level with the escape wheel. His nose was eight inches from the pallet surface. His chin was perfectly steady.
Samuel looked at the dog. Then he looked at the movement.
He pulled his loupe from his pocket and held it at arm's length, not over his own eye, but angled toward the pallet surface from above — using it as a relay lens, projecting an enlarged view of the pallet engagement into a viewing angle that his peripheral vision could read.
With Copper's chin as a stable reference point at the correct height, Samuel could position the loupe precisely without needing to press it to his eye socket.
It worked. Not perfectly, not yet, but well enough to tell the difference between even engagement and a clear mismatch.
He stood back and looked at the dog for a long moment.
"You are very clever," he said.
Copper's tail moved at sixty beats per minute.
"We are both very clever," Samuel corrected himself.
He closed his notebook. The new pallets would arrive from the machinist in Shrewsbury on Monday. The pivot hole cleaning could begin Thursday. The beat regulation session — the one that had seemed impossible a week ago — could now be planned with a working method.
He was not fixed. His eyes were still failing and would continue to fail. But the problem in front of him had been studied and a path through it had been found, which was exactly what he had done with every mechanical problem that had ever sat on his workbench.
He put on the kettle and gave Copper the last of the ginger biscuits from the tin on the shelf.
He recorded the training sessions in his workshop log with the same precision he applied to movement repairs: date, duration, what had been tested, what had worked, what had needed adjustment. The log entries were a kind of letter to his future self — the version of himself whose vision would be further gone, who would need the documented method more than the remembered one.
Copper featured in several of the entries by name, which Samuel noted was possibly unusual for a horology logbook, but which seemed to him to be simply accurate.
The relay-loupe technique was imperfect but workable, and workable was sufficient for a craftsman who had learned, over five decades, that the perfect tool almost never arrived in time for the job that needed doing.
He wrote the date at the top of the new log page and underlined it.