The result of this was that:

Two were called less, 14 per cent.
" " " equal, 36 " "
" " " greater, 50 " "

I then increased the distance of the two cards to 15 mm., the other
conditions remaining the same, and found that:

Two were called less, 11 per cent.
" " " equal, 50 " "
" " " greater, 39 " "

It will be noticed that the ratio in this last series is not
materially different from the ratio found when the two knobs of the
æsthesiometer were compared with one knob. The ratio found when the
distance was 10 mm., however, is somewhat different. At that distance
two were called greater half of the time, while at 15 mm. two were
called equal to one half of the time. The explanation of the
difference, I think, is found in the comments of one of my subjects. I
did not ask them to tell in what way one object was larger than the
other--whether longer or larger all around or what--but simply to
answer 'equal,' 'greater,' or 'less.' One subject, however, frequently
added more to his answers. He would often say 'larger crosswise' or
'larger lengthwise' of his hand. And a good deal of the time he
reported two larger than one, not in the direction in which it really
was larger, but the other way. It seems to me that when the two cards
were only 10 mm. apart the effect was somewhat as it would be if a
solid object 4 mm. wide and 10 mm. long had been placed on the hand.
Such an object would be recognized as having greater mass than a line