hand to travel between seven minutes after a
quarter past the hour, and three quarters past?" Tasks that were given
him but once would be repeated correctly upon request. The sentence:
"Bruecke und Weg sind vom Feinde besetzt" (The bridge and the road are
held by the enemy), was given to Hans one day and upon the following day
he tapped consecutively the 58 numbers which were necessary for a
correct response. He recognized persons after having seen them but
once--yes, even their photographs taken in previous years and bearing
but slight resemblance.

A corresponding high degree of sensory activity seemed to accompany
these astonishing feats of memory and reason. Although the horse is not
usually credited with a very keen sense of vision, Hans was able to
count the windows of distant houses and the street urchins climbing
about on neighboring roofs. He had an ear for the most subtle nuances of
the voice. He caught every word,--no matter how softly it was spoken--so
that we were not allowed to whisper the answer to a problem, even when
standing at a distance of several yards, since it would be
equivalent--so Mr. von Osten declared--to giving the result to the
horse.

Musical ability also comes into the category of Hans' accomplishments.
He possessed, not only an absolute tone consciousness--a gift granted to
few of us in the human world--which enabled him to recognize a note
sounded or sung to him as c, d, etc. (within the once accented scale of
c-major), but also an infallible feeling for intervals, and could
therefore determine whether two tones, sounded simultaneously, composed
a third or fifth, etc. Without difficulty he analyzed compound clangs
into their components; he indicated their agreeableness or
disagreeableness and could inform us which tones must be eliminated to
make consonance out of dissonance. C, d and e were given simultaneously
and Hans was asked: "Does that sound pleasant?" He shook his head. "What
tone must be omitted to make it pleasant?" Hans trod twice--indicating
tone "d." When the seventh chord, d-f-a-c, was sounded, he shook his
head disapprovingly. He evidently was old-fashioned in his musical
tastes and not agreeably disposed toward modern music, so he indicated
by tapping that the seventh, c, would have to be eliminated; thus
changing the seventh chord to a minor chord in order to obtain harmony.
When asked what tones might not be given simultaneously with the fourth
and sixth, Hans indica