PREFACE. 
Every day adds to the popularity of the Aquarium, but 
every day does not add to the accuracy of the published 
descriptions of it, or the perspicuity of the directions 
everywhere given for its formation and maintenance. 
Lately the periodical press has teemed with essays on the 
subject ; but it does not require a very close scrutiny for 
the practical man to discern that a majority of such 
papers express the enthusiasm rather than the knowledge 
of their authors—a few weeks’ management of a tank 
seeming to be considered a sufficient qualification for the 
expounding of its philosophy, though it demands an ac- 
quaintance with the minutest details of the most refined 
departments of botany and zoology to do anything like 
justice to it. 
I have done my best to explain and illustrate the whole 
rationale of marine and fresh-water tanks in my lately 
published work, Rustic Adornments for Homes of Taste; 
but since that work, owing to the expense incurred in its 
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