Arago's Little Joke.--a Story Of E.

axago, me f rcnon seienust: Une clay a the Acaderuy oí seiences they liad a long and rather tiresome session. Aragc thought he would go out and take the air. At the foot óf the stairway there was a leather bowl r.pon whiqh the rays of the sun were hotly bcating. Arago turned the bowl around, and rushing up stairs told the distinguished assem" blage that he had just mot with soine thiiig wliich was mysterious. ' 'Tha leather bowl," he said, "at the foot o the stairway is cool upon the side which presents itself to the sun. but warm upon the other side." The scientists descended in a body and substantiated this assertion. They took the inelination o: the sun, the hoiir, the minute, the seconds and a rast array of other details. They made calculations, and severa' weeks af tervvard eaeh of them presentec a paper explaining the phenomenon, Arago himself taking care to send in his explanation with the rest. There is no knowing how far the discussion might have gone had it not been for the conciërge; -who, havingseen Arago turn the bowl, and pitying the worthy gentlemen who were so much worrieu, clearer away the mj-sterj-.