"I don't want boys to use their pencils for improper writing"

The quote by John Burns suggests that he is worried about the use of pencils by kids for inappropriate purposes. It is likely that he is referring to the possibility of kids utilizing their pencils to draw or write improper or offending material, such as obscene pictures or repulsive language. Burns' emphasis on the word "inappropriate" suggests that he thinks there is an ideal way and an incorrect way to use pencils. He may be worried about the impact such behavior might have on the instructional environment, in addition to the capacity for damage to others. Overall, the quote suggests a desire for appropriate conduct and regard amongst students.