torn- days the water has regained its oormal clearness. As will be readily understood, the 

 management of an Aquarium is a mucli easier matter when adjacent to the sea-coast where a 

 constant supply of salt water can be obtained when required, as there is no doubt that no 

 matter how perfectly matters are arranged tlie daily supply must be beneficial ; however, in our 

 case this is impossible. So the nearest api)roach to the economy of a miniature sea is aimed at 

 by the use of the underground reservoirs and the circulation and aeration of the water. 



" Roll on, thou deep blue ocean, roll." — Byron. 



The underground reservoirs always contain three times the quantity of water that is in 

 the show tanks, and it is on the maintenance of this proportion that the successful management 

 of the Aquarium princi])ally depends. As soon as a show tank becomes turbid the water is at 

 once run otf and fresli water suj)plied from the reservoirs. 



" All the broad bosom of the ocean keeps 

 An equal motion ; swelling as it sleeps, 

 Then slowly sinking ; curling to tlie strand, 

 Faint, lazy waves o'ercreep the ridgy sand, 

 Or tap the tarry boat with gentle blow, 

 And back return in silence, smooth and slow." 



System of Aeration. 



The system of aeration adopted after long and anxious consideration was that by com- 

 pressed air. The advantages derived are manifold, the most imjiortant being that of economy, 

 and it has so far proved most successful. The air is compressed by one of K. G. Ford's 

 compressors, and stored in two cylinders 30 feet long and 3 feet in diameter, up to a pressure 



lA.S ENtilNES, AIR-COMPRESSOR, AND CYLINDERS. 



