e pass the response which merely states that it is
"easier to aim" at 50 yards. The correct principle must be given, one
which shows the subject has appreciated the fact that a small deviation
from the "bull's-eye" at 50 yards, due to incorrect aim, becomes a
larger deviation at 100 yards. However, the subject is not required to
know that the deviation at 100 yards is exactly twice as great as at
50 yards. A certain amount of questioning is often necessary before we
can decide whether the subject has the correct principle in mind.

SCORING THE ENTIRE TEST. _Two of the three problems_ must be solved in
such a way as to satisfy the requirements above set forth.

REMARKS. These problems were devised by the writer. They yield
interesting results, when properly given, but are not without their
faults. Sometimes a very superior subject fails, while occasionally an
inferior subject unexpectedly succeeds. On the whole, however the test
correlates fairly well with mental age. At the 14-year level less than
50 per cent pass; of "average adults," from 60 to 75 per cent are
successful. Few "superior adults" fail.

The test as here given is little influenced by the formal instruction
given in the grades or the high school. In fact, 80 per cent of our
uneducated business men, as contrasted with 65 per cent of high-school
juniors and seniors, passed the test. Success probably depends in the
main upon previous interest in physical relationships and upon the
ability to understand phenomena of this kind which the subject has had
opportunity to observe.

It would be interesting to standardize a longer series of problems
designed to test a subject's comprehension of common physical
relationships. In the first few months of life a normal child learns
that objects unsupported fall to the ground. Later he learns that fire
burns; that birds fly in the air; that fish do not sink in the water;
that water does not run uphill; that it is easy to lift a leg or arm as
one lies prone in the water; that mud is thrown from a rotating wheel
(and always in the same direction); that a stone which is flying
through the air swiftly is more dangerous than one which is moving
slowly; that it is more dangerous to be run over by a train than by a
buggy; that it is hard to run against a strong wind; that cyclones blow
down trees and houses; that a rapidly moving train creates a stronger
wind than a slower train; that a feather falls through the air with less