As the extent of variation did not indicate any serious error at any particular point for a watch of this description the possible poise error and the slight variation in the pinning point were waived and the regulator pins were spread just enough so that slight equal vibration of the coil could be seen with a double eyeglass. After this alteration the mean time was found to be one second per hour slow which was corrected on the mean time screws and the next test showed that the variation had been reduced to four second as per fourth column, Fig. 16. The time consumed in making the alteration aside from the repairing was less than ten minutes.
Repairs made. Refinished balance pivots and cleaned. The first test in positions disclosed a variation of thirty-five seconds as per second column Fig. 17.
Investigation found the balance true; hairspring true, level and circle; regulator pins very nearly closed and the motion one and one-eighth turn. This rate like example No. 1, was also fast in the pendant up position, but the greater extent of the error indicated that there must be some serious poise error, and upon investigation this was found to be the case. A screw on the roller jewel side or at the bottom when the balance was at rest was found to be heavy. This was corrected and the next test showed a much improved rate although there was still a variation of eight seconds fast pendant up as per fourth column Fig. 17.
+--------------------------------------------------+ | No. _B060816_ Make _Ball_ | +--------+-----+-----+-----+-----+-----+-----+-----+ | D U | + 2 | + 2 | + 7 | + 7 | + 7 | + 7 | P | +--------+-----+-----+-----+-----+-----+-----+ | | D D | + 2 | 0 | +14 | + 7 | +14 | + 7 | | +--------+-----+-----+-----+-----+-----+-----+ | | P U | +37 | +35 | +29 | +15 | +24 | +10 | | +--------+-----+-----+-----+-----+-----+-----+-----+ 35 8 3
A better rate than this was desired and further examination proved that the locking of the pallet stones and escape teeth was quite strong and caused the pendant up motion to have a shorter arc than would have been entirely desirable. An alteration was made by pushing the receiving stone further back into the slot and rebanking the escapement. The third position test showed an improved motion and a variation of three seconds as per sixth column. The total time required for making the alterations was about three quarters of an hour.
