Omaha daily bee., 1910-04-24

employed for timing the Ormond and Day
tona races II works with the utmost pre-
cision. is entirely automatic. and makes
printed record Of the race reading to hum
dredths Of a second. The necessity Of such
great refinement Of timing will be appreci-
ated when one considers that the lightning
Benz" during it's record mile run was trav-
cling at the rate Of 231s inches at every
hundredth Of a second
Mr. Warmers instrument consists OF four
type wheels one Of which indicates hours,
the next minutes. the third seconds and
the last one hundredths Of a second The
wheels are operated after the manner Of
an odometer instrument. over the wheels
runs strip OF paper, and above that a
typewriter ribbon, and record is made by
a hammer actuated by an electro-magnet,
which strikes the ribbon and paper against
the type wheels. In the circuit OF the mag
net which operates the hammer is a relay
switch controlled by an electromagnetic in
circuit that is normally closed. This
closed circuit is connected with the start
ing and finishing tapes. or with tapes at
other points where IL is desirable TO record
the time. The tape consists Of a wire
stretched across the course at a height
Of few inches from the ground, and this
wire is connected to switch ingeniously
constructed to be opened by the shock
rather than an increase of tension when
the wire is struck by the wheels of an
automobile, When the switch opens the
instrument prints record. The type
wheels are frietionally mounted on driv-
ing shaft which is rotated by an electric
: motor. At the start Of the race they are
held stationary. and are not released until
the starting wire is depressed, when they
print zero and they begin their revolutions
The hundredths wheel makes a revolution
every two seconds.
ChrOROmeter Checks.
Obviously, the most important part of the
instrument Is the regulation Of the electric
motor which drives the type wheels. 1t is
| impossible TO construct a motor so perfect
OF a storage battery that will discharge so
uniformly that there will not be the slight
est vibration in the rotation OF the driving
shaft. However, the instrument Is so ar
ranged that at the end of every second its
| speed is automatically checked up with an
accurate chronometer. At one end of the
| driving shaft Is a double-armed lever. and
1 In the path OF this arm is a small catch
| connected with the armature of an electro
magnet. The chronometer acts through g
relay circuit to energize this magnet every
second, thus moving the catch ont of the
path of each arm of the lever The motoi
is regulated to turn the shaft ever sc
lightly faster than one turn in two seconds
| so that each arm strikes the catch just ar
instant before 1t is Withdrawn. Secured tC
the base OF the instrument at one side Is 4
little ''telltale" Indicator, forming tho ar
mature OF an electro-magnev. The circuit
Of the magnet is closed whenever the arm
and catch contact, thus giving the "telltale'
a slight throb every second. The operator
of the instrument watches this "telltale,
one hand on the governor of The elsctrit
motor and II the ''telltale" indicator in
gers too long at each contact Of the arm
and catch he slows up the motor a trifle
j whereas il the 'teltale" fails to register
a contact he speeds up the motor slightly
so that the arm will strike the catcn jus