THE FOUNTAIN. 273 



reservoir, at some distance above the level of the 

 Tank, in a higher story for example, whence a sup- 

 plying tube may descend, and passing beneath the 

 floor, ascend through the foot of the vase, to the sur- 

 face of the water. All the visible portion may be 

 easily concealed among the rock-work ; while from 

 the extremity a jet would play, proportioned in force 

 to the weight of the supplying column, or, in other 

 words, to the height of the reservoir above the surface. 

 It would be needful to make the apparatus of some 

 incorrodible material ; — gutta percha, for instance, for 

 the tube, with a nozzle of glass ; — as metals would 

 be acted on by the sea-water, and form noxious 

 oxides. The water might either be carried up to the 

 reservoir, or pumped up by an obvious extension of 

 the apparatus. 



Such a modification would doubtless be as efficient 

 as it would be elegant. The constant, or at least, 

 frequent dissemination of the water through the air 

 would keep the whole volume in agreeable coolness, 

 as well as maintain its sparkling clearness and purity. 



Evaporation.- — If the Tank remain habitually un- 

 covered, or protected only by a coverlid of muslin, 

 daily evaporation will soon reduce the volume of the 

 water, and increase its specific gravity. The pure 

 water alone rises in vapour, the various gaits held in 

 solution, remaining the same in quantity, though the 

 water should be reduced to half its original bulk. It 

 is therefore needful that additions of pure/resA water 

 (not sea-water) be made from time to time, to replace 

 the loss by evaporation. Distilled water is of course 

 the best, but, practically, river-water will answer per- 



