The Washington times., 1915-01-25
Uncle Sam Launches Campaign to
DO A1vay With Adulterated Time
Certificate as to Worth Of Time.
piece to Be Given All Who
Want II.

Then the series Of position tests 10 re-
peated In reverse order.
The watches are kept in . compart-
ment that resembles q large refrigere
tor with glass on three sides. In THIS
compartment ID maintained constant
The thermostst is used 80. that varia-
tions Of temperature. caused by opening
the door, are automatically corrected
by the lighting Of additional electric
lamps. A thermograph In used to record
the temperature. For low temperature
large brine coil above the compart-
ment II provided so that the air may De
pumped through 1t, and thus cool It 10
the freezing point II necessary.
Readings Through Telescope.
Readings Of the watches are made
! through q small telescope. placed IN
front Of the glass testing case. These
readings are recorded on . chronograph.
! by means Of 4 telegrapher's key and
! wire. This chronograph 10 connected to
the electric seconds contact nf the
bureaus meantime clock. The tele;
Of the watch reaches the fifty-elShtn
sixtieth and second second hand marks
/ on the dial. Thus the correction OF the
watch for each day Is obtained within
| one-tenth Of a second.
This chronograph contains a cylindri-
! cal drum. on which IL placed sheet OF
| paper. The pen moves along this chart.
| and makes q slight deviation, as the
bureaus precision clock, at the rate of
one second per centimeter.
Both the !sochronism and temperature
| tests are carried on wit hthe temper
ature under thermostatic control. For
temperature tests the watca IL run nye
days at s. 20, and Is Centigrade az. S.
and s5 Farenheit). There is an unavoid-
able variation Of timepiece. graphic
ally represented by q parabola. and fh,s
IL allowed for by the tests. watch
usually runs faster at medium temper
| ature than at low Or high 80 the
| graphic representation IL made by a
parabola. in reports on the temperature
| test.
Represented BY Curve.
The sochronism test ~ represented by
a curve. A straight line is drawn from
the point of winding through squares
representing each hou:. The amount OF
deviation OF the isochronism curve from
this straight line indicates the relative
isonchronal adjustment.
The chronosrap ph, by which the read
ings are recorded, Is controlled by the
precision meantime clock. one on the
| most interesting pieces " mechanism q:
the bureau. Tins clock Is n an air
mospheric pressure, AMI winds ,tsc!l
every thirty seconds by means OF ar
| electric contact device. A small arr
then falls slowly until It again tnI"hcs
the point OF contact and Is rep".led C
the position from which 1t slowly fails.
How delicate the adjustment OF thti
clock Is is indicated by the fact that g
change Of the pressure within the glasi
case which would change the mercur,
level by one mlllimeter the thickness
Of the lead in a penciD would change
the rate Of the clock fourteen-thou
sandths Of a second.
Free From All Changes.
This timepiece Is affixed to marble
slax six inches thick. and Is kept In I
room with tiled walls. These WALL
are surrounded by a two-inch al
chamber, and by a three-foot concrete
wall Against the walls. on three sides
Is earth. and at tho entrance are thre.
doors and two vestibules. also Will
tiled walls. and extra ceilings. SO th'
clock may be free from Temperature
changes outside. The temperatur,
within the compartment does not var!
more than one-tenth Of degree. Cent?
grade, per week.
In making the experiment hft!
watches were borrowed from Wash
ington jewelers.. Watches also wer'
obtained from American manufacturer
OF whom there are only about ten
Tests will be made to determine whethe
Amcrlcan-made watches are superior t
those made abroad.