284 GENERAL DIRECTIONS. 



form of the invention particularly suitable for a con- 

 servatory or hall. It needs but a vessel, fixed as a 

 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 reser- 

 voir, 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. 



In a well-regulated Tank, however, none of these 

 modes are necessary. My oldest reservoir, which has 

 been in constant occupation for two years and six 

 months, never has any artificial aeration, except an 

 occasional syringing, and that is often intermitted for 

 months together. The surface is now and then agi- 

 tated with a stick, and broken by the addition of fresh 

 water to supply the loss by evaporation, and this is 

 all the external aid it receives. Yet the water gene- 



