53 



to secure a perfect circulation aud cliange of water which is 

 constantly flowing tliTough them. The water having passed 

 through the upper troughs furnishes the lower pair, dropping 

 down through a space of about 18 or 20 inches, it is com- 

 pletely broken and aerated. 



Those marked "C"' are arranged so as to cause the water 

 to enter at the bottom of the trays in eacl»i division; flowing 

 up througli them, and over the top of the partition, is con- 

 ducted into the next division from below. This is the form 

 of hatching box designed by J(din Williamson, Secretary of 

 the California Acclimatizing Society. The troughs marked 

 "D" are so arranged that the v/ater takes just tlie opposite 

 course, entering at the top of the trays, it flows down through 

 them. This device is patented by N. W. Clark, of Michigan, 

 who has kindly permitted their use by us, without charge. 

 At "B'" there are two flights of Coste trays, after the model 

 of those used at Humingen and elsewhere in Europe. "K" 

 are hatching boxes, as patented by Green & Holton, and so 

 successfully used in the hatching house of the New York 

 Commission. The right to use them was kindly accorded lis 

 by Seth Green, Esq.^. the assignee. 



In aquarium ^'F" which is supplied with running water, 

 we intend exhibiting rare flshes, from time to time. The 

 porcelain lined sinks "H,"' furnished with the same water 

 whicli is used in tlie troughs, are of great convenience. All 

 the water, save that from the sinks, after lieing used in the 

 hatching house, is conducted into the ponds below the build- 

 ing. The coste trays and the troughs next to them can be 

 removed at any time without interfering with tlie flov/ of 

 water, and can be replaced by stoves oi- aquaria as desired. 

 It is scarcely probable that it will be found necessary to use 

 stoves as the spring water entering the building at a tem- 

 perature of 53° Fahrenheit, and being ex])osed in the closely 

 built stone building, the temperature is kejjt mucli above 

 freezing. The two rooms above, in the second story, are oc- 

 cupied respectively as office and sleeping apartment for keeper. 

 The moisture is cut off from the second story, by a layer oi" 

 slate in the walls. 



We are indebted to the City of Baltimore and the Park 

 Commissioners for this most complete, comfortable, and per- 



