Courier Democrat. (Langdon, N.D.) 1891-1920, 1895-09-19
SCIENTIFIC MATTERS
INTERESTING REFORMATION ABOUT
THE USEFUL ARTS.

INTERESTING REFORMATION ABOUT
THE USEFUL ARTS.
Wonderful Time - MeNsurlng In
strument-A Bicycle Lawn Mower
Deep-Sea PhOtOgraphy-Scien
HyRtene-ScientiflcN Notes.
Much interest has been aroused In
the scientific circles Of Europe by
what Is claimed to be the most won
derful timing chronoscope, invented In
this country by Prof. C. b. Bliss. and
perfected In the psychological labora-
tory. of Yale by j. j. Hogan. 1t can
be used with the luickness of stop
watch. without the help of either cleo
trician or mathematician. 1t measures
accurately down to the one-thousandth
part of second, and is already tax
ing the place of the old-style chrome
scopes in scientific laboratories. The
instrument and electrical attachments
1t tells the speed of cannon ball,
the lapse of time between the firing of
u pistol and the starting Of runner.
land it is proposed to introduce it into
boxing schools, so that pupils can con-
stantly test the speed with which they
can deliver blow. and so note the
lessening the reaction time between
the brain impulse and the blow on
which increase of skill depends. The
machine consists of pendulum and
pointer swinging Independently on the
same axle. The tip Of the pointer
travels along the face of the curved
scale or indicator, which is graduated
to show the one-thousandth Of a Sec
ond. To measure the time required
for the transmission of any given i'm
preston a button is pressed. This
sets the pendulum in motion, and the
result is registered on the scale. If
sight test has to be made, when the
pendulum comes in contact with the
pointer black shutter is raised from
light disk. AS the disk flashes on
the sight of the object he touches
button and the pointer is instantly
stepped. Tie average time between
and the pressure of the button has
The reflex action for sound is quicker
than this, being put at O.13O of a sec
Ond. The discerning Of cOlOrs Is look
CA uPOA 40 &lA APSA SoAI SOoS IA IAO
determination of certain traits of the
pupils. \ square of some color I'M
known to the subject is to be exhibit
ed from behind shutter He is told,
for instance, to press the button when
be sees blue. This test sometimes ex-
tends to One-Quarter Of a second. The
trials With odors. noises and pinpricks
are very interesting. The object Of
these tests in school work is to enable
teachers to ascertain the mental char
acteristics of their scholars. Under
the old system of teaching, all the
scholars in class were grouped to-
gether. and subjected to the same in
flexible rules of tuition, regardless of
their differences of temperament and
intellectual ability. The chronoscope
puts an end to such crude methods,
and reduces teaching to a science.
A Bicycle Lawn Mower.
Thomas Caldwell, who is supposed
to have taken out more patents on
lawn mowers than anybody else in the
world, was talking the other day with
William I. Hilton about arranging
chains and pedals in such way as
to drive small horse mower by man
power. when his 19-year old son Harry
spoke up:
"Why don't you make big hand
, mower and attach it to the front Of the
bicycle in place of the front wheely
he asked.
The boys suggestion was tried, and
the invention of the mower cycle was
the result. The machine is made with
al ordinary bicycle hind wheel and q
9O-inch mower in .he place of the
front wheel. The mower wheels have
rubber tires aud they run just as
smoothly as bicycle itself. 1t is at
tachcd with long steel prongs or forks,
ard may be adjusted to cut high or
low. The pedals are placed directly
on the large wheel shaft, dispensing
with the chain sprocket wheels and
crank shaft of the bicycle. The strain
oe pushing the mower is taken off the
frame and head Of the machine by two
rods, ono OH each side Of the large
wheel, one end of which is attached
to the frame at the center Of the
wheel. and the other to the mower
The machine turns more readily than
a bicycle-in fact, may be turned
around in 6-foot circle. 1t takes no
more power to operate it than to pro-
pei an ordinary tricycle.. 1t is not yet
perfected to run on side hill, but Mr..
Caldwell expects to overcome this lit