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CUTTING INSTRUMENTS. 23 :
may be easily learned and remembered, we confine the set to a
regular range of sizes and range of angles of blades that will
give an orderly set for practical use and a sufficient variety of
forms. In this way, unnecessary multiplication of forms is pre-
vented.
THE METRIC SYSTEM OF MEASUREMENT.
There is but one possible way of learning any system of
measurement and that is by using it. The denominations of the
system may, however, be learned from books. In the metric
system these denominations, so far as our uses in dentistry
require, are
Meter 39 inches approximately.
Decimeter, tenth of a meter 4 " "
Centimeter, hundredth of a meter ... f " "
Millimeter, thousandth of a meter. • . ^V " "
Tenths, himdredths and thousandths of a millimeter.
Thousandths of a millimeter are called microns. The micron
is used only in microscopic measurements. In measurements of
ordinary small bulks of liquids, or of solids, the cubic centimeter
(abbreviation c.c.) and the liter are the principal denominations
used. Hei'e the measurement is of the three sides of a cube, thus
10 X 10 X 10 == 1,000. Therefore, there are one thousand cubic
centimeters in one liter of water or other liquid. This is all sim-
ple enough for any one to understand at a glance, but to really
know what it means or to know it in use so that one may have an
actual knowledge of what the terms and figures mean, requires a
wide, practical use of it.
DENTAL INSTRUMENT GAUGE.
ILLUSTRATION: FIGURE 17.
This gauge for dental instruments is used especially in the
measurement of excavators, pluggers and burs. It is in the metric
system. The smaller gradations on the principal bar are milli-
meters. The gradations of the width of the slot formed by the
smaller bar on the left are tenths of millimeters. The circular
head has one hundred divisions — centigrades — for the meas-
urement of angles. It is used as follows
1. Measure the width of the blade in the slot numbered
from to 50, which gives the width in tenths of a millimeter. In
this case the tenth millimeter is used as the unit and entered as
a whole number. This is the first figure in the formula.
:
CUTTING INSTRUMENTS. 23 :
may be easily learned and remembered, we confine the set to a
regular range of sizes and range of angles of blades that will
give an orderly set for practical use and a sufficient variety of
forms. In this way, unnecessary multiplication of forms is pre-
vented.
THE METRIC SYSTEM OF MEASUREMENT.
There is but one possible way of learning any system of
measurement and that is by using it. The denominations of the
system may, however, be learned from books. In the metric
system these denominations, so far as our uses in dentistry
require, are
Meter 39 inches approximately.
Decimeter, tenth of a meter 4 " "
Centimeter, hundredth of a meter ... f " "
Millimeter, thousandth of a meter. • . ^V " "
Tenths, himdredths and thousandths of a millimeter.
Thousandths of a millimeter are called microns. The micron
is used only in microscopic measurements. In measurements of
ordinary small bulks of liquids, or of solids, the cubic centimeter
(abbreviation c.c.) and the liter are the principal denominations
used. Hei'e the measurement is of the three sides of a cube, thus
10 X 10 X 10 == 1,000. Therefore, there are one thousand cubic
centimeters in one liter of water or other liquid. This is all sim-
ple enough for any one to understand at a glance, but to really
know what it means or to know it in use so that one may have an
actual knowledge of what the terms and figures mean, requires a
wide, practical use of it.
DENTAL INSTRUMENT GAUGE.
ILLUSTRATION: FIGURE 17.
This gauge for dental instruments is used especially in the
measurement of excavators, pluggers and burs. It is in the metric
system. The smaller gradations on the principal bar are milli-
meters. The gradations of the width of the slot formed by the
smaller bar on the left are tenths of millimeters. The circular
head has one hundred divisions — centigrades — for the meas-
urement of angles. It is used as follows
1. Measure the width of the blade in the slot numbered
from to 50, which gives the width in tenths of a millimeter. In
this case the tenth millimeter is used as the unit and entered as
a whole number. This is the first figure in the formula.
