we undertook the test the horse's far-famed
knowledge of the calendar. Dates, such as Feb. 29, Nov. 12, etc., were
given to Hans and he was asked to indicate on which day of the week they
fell. Sunday was to be indicated by 1, Monday by 2, etc. Of 14 such
tests, 10 were unsuccessful, 4 successful. But in the case of these 4
something very interesting occurred. It happened that during this series
the keeper of the horse was present, and he happened to know the days on
which these dates fell,--as he himself testified. The dates in question
were also little more than a week or so from the day of the experiment,
so they could easily be determined. But as soon as we took more remote
dates both man and beast were hopelessly lost. It was certain that Hans
had no knowledge of the calendar. It is needless to say anything of his
supposed knowledge of cards and coins. Hans plainly was incapable of
the astonishing feats of memory which had been claimed for him.

Finally we investigated Hans' musical ability. In a room adjoining the
horse's stall there was a small harmonica, which spanned the once
accented octave. On this one or more tones were played. The horse was
required to indicate the tone played, the number of tones played and
their relation to one another. For testing his general hearing 20 tests
were given in which the method was procedure without knowledge. Of the
responses only one was correct, and that one was the tone e, for which
the proper response was three taps, but we must bear in mind what has
already been said of the number 3. The tone b was indicated by 11 taps,
although Hans had only learned a scale of one octave and therefore could
respond to only seven tones. In the tests in which the method was
procedure with knowledge, he again, without exception, was successful.
Similar results were obtained in the analysis of compound clangs. In the
cases of procedure without knowledge (although the experimenter here
knew the correct responses, he purposely refrained from thinking of
them) not a single response was correct; while in the cases of procedure
with knowledge, all but one were correct. The following were typical
responses: Three tones were played and the question was asked, "How many
tones were played?" Hans responded first with 4 taps and then with 1.
The tones c, e, g, a, (1, 3, 5, 6) were struck and the question asked,
"Which tone must be eliminated to make the complex a chord?" In the
tests in which the met