day. I We studied physics all my life, but it's to-day for the first time that I learn that a body which has no weight cannot be thrown around, or that it cannot break a glass vase if thrown with sufficient force."
Mr. Curtis looked a little sheepish at this burst of sarcasm, but he felt so sure of his position that he replied:
"Why, doctor, the same thing happens here on earth with bodies that have little or no weight. Give a feather to the strongest man alive, and, because it has little or no weight, he will only be able to throw it a few inches, even though he exerts his utmost strength, whereas he could throw a heavy base-ball quite a distance."
"That's true enough," said the doctor.
"Well, now let the same man take that feather and throw it down with all his might against the most delicate glass vase, and yet he won't be able to harm the vase in the least."
"That is also true," said Dr. Giles; "but the reason is not, as you seem to think, because the feather has little or no weight."
"What is it, then?"
"It is because the feather has almost no mass."
