[87] FISHERIES OF THE UNITED STATES. 599 



Large faucets to draw off salt water are placed at each sink ; and by a 

 proper arrangement of valves it is possible to lead fresh water to a part 

 of the pipes in case it is needed. The pipes leading over the tables and 

 shelves are provided with globe valves and nozzles, to which rubber pipes 

 can be attached and the water led to a vessel below. There are fifty 

 such taps, each of which can supply water or air to at least three or 

 four jars. The overflow runs into gutters laid alongside the tables, 

 leading into the main drain pipe. To aerate the salt water, I use an in- 

 jector invented by Professor Richards, of the Institute of Technology. 

 This can be used to supply aerated water directly to the jar by provid- 

 ing it with a siphon overflow, or the aerated water can be collected in 

 a receiver, from which air alone is then led to the jar. This latter 

 course is the only practical one for delicate specimens, and for the bulk 

 of the work of raising embryos. The east and west sides have large 

 windows and doors provided with blinds. They always remain open, 

 with the blinds closed to keep out sunlight, and serve to ventilate the 

 laboratory thoroughly. Large tables for dissection, covered with slate, 

 and adjoining a sink provided with fresh and salt water, are placed 

 across the windows of these sides." 



MAPS, MODELS, AND COLLECTIONS OF NATURAL HIS- 

 TORY, ILLUSTRATING RESULTS OF EXPLORATIONS. 



Relief Model of the western part of the North Atlantic, from Newfoundland 

 to, and including, the Gulf of Mexico; based principally upon recent 

 explorations by the United States Coast Survey steamer Blake and 

 the soundings of H. M. S. Challenger, in 1873. Constructed under 

 the direction of J. E. Hilgard, Superintendent of the United States 

 Coast and Geodetic Survey, by A. and H. LiDdenkohl, 1883. 

 Horizontal scale, aroo-ooo j vertical scale, 1,000 fathoms to one inch. 



Relief Model of the Gulf of Maine, based upon the soundings of the United 

 States Coast and Geodetic Survey, and constructed for the United 

 States Commission of Fish and Fisheries, by A. and H. Linden- 

 kohl, 1883. 



Scale, otoVoo- The signs " + " denote dredging stations of the United 

 States Fish Commission, from 1871 to 1882. 



Relief Model of the off-shore fishing-banks of Eastern North America, from 

 New York to the eastern edge of the Grand Banks. Constructed 

 for the United States Fish Commission by A. Lindenkohl. 



Horizontal scale, 12 dnnnx; vertical scale, y^w? j ratio of horizontal 

 scale to vertical as 3 : 50. 



Series of Charts and other Publications of the United States Coast and Geo- 

 detic Survey, showing sounding aud dredging operations, &c. (For 

 list see elsewhere in catalogue.) 



