No. 47. A Fountain which trickles by the Action of the Sun's Rays. THE "fountain" as it is called may be made to trickle as long as the sun falls upon it. Let there be an airtight pedestal, A B C D (Fig. 47), through which a funnel is inserted, its tube extending within a very little of the bottom. Let E F be a globe, from which a tube leads into the pedestal, (reaching nearly to the bottom of the pedestal and to the circumference of the globe,) while a bent siphon, fitted into the globe, leads into the funnel. Now pour water into the globe; and when the sun falls upon the globe, the air in it, being heated, will drive out the liquid, which will be carried along the siphon G;, and pass through the funnel into the pedestal. But when the globe is in the shade, the air having escaped through the globe, the tube will again suck up the liquid, and fill the void which had been produced; and this will take place as often as the sun falls upon the globe.