Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1879-03-27

NH "A MATHEMATICAL DOG.
Feats of q Talented Canine WhIo1. Kne,c
H0tv to Ertract Square Root.

| 3 n6Vl0W.l
The well known spectroscopist and astron-
omer, DR.. Higgins, had four-footed friend
dwelling with him for many years as a regu-
lar member Of his household, who was
mastiff of very noble proportions by descent,
and who bore the great name of Kepler.
| This dog possessed many rare gifts
! which had secured for him the admira-
ton and regard of a large num-
Der OF scientific acquaintance, and among
| them there was one which he was always
| ready to exercise for the entertainment of
visitors. AT the close of luncheon or din
| ner, Kepler used to march gravely and Sc
dately into the room and set himself down
at his masters feet. DR.. Higgins then pro-
pounded to him series of arithnnetical
questions, which the dog invariably solved
without mistake. Square roots were ex-
tracted off-hand with the utmost readiness
and promptness If asked what was the
square root of 9, Kepler wonld reply by
three barks; or, if the question were the
square of 16, by four. The various ques-
tons followed, in which much more compli-
Gated processes were involved-such, for in
stance, as ''add Z to 8, divide the sum by 8,
and multiply by e. To such a ques-
ton as that Kepler gave more consideration,
and sometimes hesitated in making up his
mind as to where his barks ought finally to
stop. Still, in the end, his decision was al
ways right. The reward for each correct
answer was piece of cake, which was held
before him during the exercises; but until the
solution was arrived at Kepler never moved
his eye from his masters face. The i'll
slant the last bark was given he transferred
his attention to the cake DR.. Higgins was
perfectly unconscious of suggesting the
proper answer to the dog, but it is beyond
all question that he did so. The wonderful
fact is that Kepler had acquired the habit of
reading in his masters eye or coun-
tenance some indication that was not
known to DR.. Higgins himself.
The case was one of the class which is
distinguished by psychologists as that of ex-
pectant attention. DR.. Higgins was himself
engaged in working out mentally the various
stages of his arithmetical processes as he
propounded the numbers to Kepler, and, be-
ing therefore aware of what the answers
should be, expected the dog to cease barking
when that number was reached, and that ex
pectation suggested to his own brain the un-
conscious signal which was caught by the
quick eye Of the dog. The instance is strict
ly analogous to the we'll known case in which
button, suspended from thread and held
by finger near to the rim of glass, strikes
the hour of the day as it swings, and then
stops-that is, provided the person who holds
the button himself knows the hour! The ex-
PLANTATION of this occurrence is that the hand
which holds the button trembles in conse-
quence of its constrained position, and III
that way sets the button swinging, and as
the attention of the experimenter is fixed
upon the oscillation, in the expectation that
definite number of strokes upon the glass
will occur, his own brain convolutions take
care that the movements of the finger shall
be in accordance with that expectation.
The mathematical training of poor Kepler
has, unfortunately, come to an untimely
end. The interesting arithmetician died of
an attack of typhus fever, to the great
sorrow OF his large circle of friends, at the
beginning of last year, and he now sleeps
under the shadow of the telescopes at Tulse
hill. The memory of his high attachments
and of the distinguished success with which
he upheld the reputation of his name, how
ever, remains His most intimate friends
also enjoy the consolation of an excellent
portrait of his thoughtful face, lit up with
the exact expression which it bore when he
was engaged with his arithmetical prob
lens.