This point is covered in Chapter XI, No. 47.

[71.]Example No. 9.

E. Howard. No. 1,116,735. Open Face, 23 Jewels.

Repairs made. New balance staff; hole jewel; mainspring and cleaned.

The first test in positions showed a variation of eleven seconds. The rate in all positions was fast with the exception of the dial down rate, which was slow. See Fig. 26.

At first glance it might appear that by causing a faster rate of six or seven seconds in the dial down position the watch would have a very good rate. This, however, would not be consistent unless the rate was due to the exception referred to in Chapter XI, No. 50.

Examination of the motion in the horizontal positions proved that it was about one fourth turn better in the dial down position than it was in the dial up position which rate compared very closely with the vertical positions. It was therefore evident that the dial up rate was not true and investigation found the oil in the upper jewel had become thickened by the entrance of dirt which caused the short motion and fast rate when the balance was running on this end stone.

Fig. 26
No. ...1116735.......... Make...E. Howard.......
D U+ 2+ 2- 5+ 2+ 2+ 2P
D D- 3- 5-10- 5+ 4+ 2
P U+ 1+ 4- 6+ 4+ 9+ 5
P R+ 7+ 6 0+ 6+10+ 1
P L+ 9+ 2+ 2+ 2+14+ 4
11 11 4

After thoroughly cleaning the jewel, end stone and pivot, the motion in the dial up position was improved and equaled that of the dial down position.

The next position test showed the horizontal rates to be equal but the variation of eleven seconds in the five positions still existed as per fourth column Fig. 26. The vertical rates were all fast compared to the horizontal; the regulator pins were found to be slightly open which prevented a correction at this point. The locking of the escapement was examined and found to be satisfactory, so the balance was again removed and tested for poise which was also found satisfactory.