SCORING. There are four types of response: (1) A straight diagonal line is drawn from the cannon's mouth to the point where the ball strikes. (2) A straight line is drawn from the cannon's mouth running horizontally until almost directly over the goal, at which point the line drops almost or quite vertically. (3) The path from the cannon's mouth first rises considerably from the horizontal, at an angle perhaps of between ten to forty-five degrees, and finally describes a gradual curve downward to the goal. (4) The line begins almost on a level and drops more rapidly toward the end of its course. Only the last is satisfactory. Of course, nothing like a mathematically accurate solution of the problem is expected. It is sufficient if the response belongs to the fourth type above instead of being absurd, as the other types described are. Any one who has ever thrown stones should have the data for such an approximate solution. Not a day of schooling is necessary. (b) _Problem as to the weight of a fish in water_ PROCEDURE. Say to the subject: "_You know, of course, that water holds up a fish that is placed in it. Well, here is a problem. Suppose we have a bucket which is partly full of water. We place the bucket on the scales and find that with the water in it it weighs exactly 45 pounds. Then we put a 5-pound fish into the bucket of water. Now, what will the whole thing weigh?_" SCORING. Many subjects even as low as 9- or 10-year intelligence will answer promptly, "Why, 45 pounds and 5 pounds makes 50 pounds, of course." But this is not sufficient. We proceed to ask, with serious demeanor: "_How can this be correct, since the water itself holds up the fish?_" The young subject who has answered so glibly now laughs sheepishly and apologizes for his error, saying that he answered without thinking, etc. This response is scored failure without further questioning. Other subjects, mostly above the 14-year level, adhere to the answer "50 pounds," however strongly we urge the argument about the water holding up the fish. In response to our question, "_How can that be the case?_" it is sufficient if the subject replies that "The weight is there just the same; the scales have to hold up the bucket and the bucket has to hold up the water," or words to that effect. Only some such response as this is satisfactory. If the subject keeps changing his answer or says that he _thinks_ the weight would be 50 pounds, but is not certain, the score is failure. (c) _Difficulty of hitting a distant mark_