[Illustration:  Fig. 66]

Now such other condition might very easily exist, that bringing the jewel pin forward to the position indicated by the dotted lines at D, Fig. 66, would remedy the defect described and illustrated at Fig. 64 without any other change being necessary.  We do not assert, understand, that a hole too large for the jewel pin is either necessary or desirable—­what we wish to convey to the reader is the necessary knowledge so that he can profit by such a state if necessary.  A hole which just fits the jewel pin so the merest film of cement will hold it in place is the way it should be; but we think it will be some time before such rollers are made, inasmuch as economy appears to be a chief consideration.

ABOUT JEWEL-PIN SETTERS.

To make a jewel-pin setter which will set a jewel pin straight is easy enough, but to devise any such instrument which will set a jewel so as to perfectly accord with the fork action is probably not practicable.  What the workman needs is to know from examination when the jewel pin is in the proper position to perform its functions correctly, and he can only arrive at this knowledge by careful study and thought on the matter.  If we make up our minds on examining a watch that a jewel pin is “set too wide,” that is, so it carries the fork over too far and increases the lock to an undue degree, take out the balance, remove the hairspring, warm the roller with a small alcohol lamp, and then with the tweezers move the jewel pin in toward the staff.

[Illustration:  Fig. 67]

[Illustration:  Fig. 68]

[Illustration:  Fig. 69]

[Illustration:  Fig. 70]

No attempt should be made to move a jewel pin unless the cement which holds the jewel is soft, so that when the parts cool off the jewel is as rigid as ever.  A very little practice will enable any workman who has the necessary delicacy of touch requisite to ever become a good watchmaker, to manipulate a jewel pin to his entire satisfaction with no other setter than a pair of tweezers and his eye, with a proper knowledge of what he wants to accomplish.  To properly heat a roller for truing up the jewel pin, leave it on the staff, and after removing the hairspring hold the balance by the rim in a pair of tweezers, “flashing it” back and forth through the flame of a rather small alcohol lamp until the rim of the balance is so hot it can just be held between the thumb and finger, and while at this temperature the jewel pin can be pressed forward or backward, as illustrated in Fig. 66, and then a touch or two will set the pin straight or parallel with the staff.  Figs. 68 and 69 are self-explanatory.  For cementing in a jewel pin a very convenient tool is shown at Figs. 67 and 70.  It is made of a piece of copper wire about 1/16” in diameter, bent to the form shown at Fig. 67.  The ends b b of the copper wire are flattened