Labor-saving rules
49
provided with fine saws for cutting thicker bodies, and with mitring adjustments for any angle. Rules of prescribed length should first be cut by trifle longer than seems needed, and afterward trimmed down by the side-plane of the ordinary machine. Mitred rules should be tested
the gauge a
and square stick before they are used, for sometimes happens that a set of rules may be cut of true length as to face, but over-long as to foot. A slight deviation will prevent a true joint. Sideplaning must always be done quickly and with force. If done feebly and timidly upon a weak machine, in a true it
the rule
may
spring or the plane
may jump and
produce an uneven cnt. The face of the rule should be first met by the plane if the foot first meets the plane, a rough edge may be left on the face. Most mitring-machines have dials accurately marked for In cutting a set of mitred rules different angles. for a border, the gauge must be set alternately at ;
equal distances from the right-angled line on the The machine is to be preferred that firmly holds the rule, so that it will not spring. dial.
A
miscellaneous stock of brass rules
to keep in order.
The labor-saving
is difficult
rules furnished
by the type-founder are usually cut to ens of pica for all the smaller lengths but any house may need rules of intermediate size, and the irregular lengths ;
should be kept apart in a separate case.
A
Labor-saving rule cases are made to many plans. diagram that follows shows a rule case made to 4