With the dividers set so one leg rests at
the center _m_ and the other leg at the point _d_, we sweep the arc _t_.
With the dividers set at 1.33" we establish on the arc _t_, from the
point _d_, the points _e e'_, which locate the position of the pillars
_E E'_. The outside diameter of the balance _B_ is 3-5/8" with the rim
3/16" wide and 5/16" deep, with screws in the rim in imitation of the
ordinary compensation balance.
Speaking of a balance of this kind suggests to the writer the trouble he
experienced in procuring material for a model of this kind--for the
balance, a pattern had to be made, then a casting made, then a machinist
turned the casting up, as it was too large for an American lathe. A
hairspring had to be specially made, inasmuch as a mainspring was too
short, the coils too open and, more particularly, did not look well.
Pallet jewels had to be made, and lapidists have usually poor ideas of
close measurements. Present-day conditions, however, will, no doubt,
enable the workman to follow our instructions much more readily.
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