598 FISHERIES OF THE UNITED STATES. [86] 



greater facility in detecting minute animals on a black background. 

 Between the windows movable brackets with glass shelves are placed; 

 while similar brackets extend across the windows and between the 

 tables, thus providing a shelf at any desired height. The tables for 

 microscopic work are three-legged stands of varying height, adapted to 

 the different kinds of microscopes in use. The whole of the northern 

 side of the floor, upon which the work tables and microscope stands are 

 placed, is supported upon brick piers and arches, independent of the 

 main brick walls of the building, which form at the same time the base- 

 ment of the building. The rest of the floor is supported entirely upon 

 the outside walls and upon columns with stretchers extending under the 

 crown of the arches reaching to the northern wall. This gives to the 

 microscope work the great advantage of complete isolation from all 

 disturbance caused by walking over the floor. This will be duly ap- 

 preciated by those who have worked in a building with a wooden floor, 

 where every step caused a cessation of work, and was sure to disturb 

 any object just at the most interesting moment. The floor is cemented 

 and covered by a heavy oil cloth. The center of the large room is oc- 

 cupied by a sink, on each side of which extend two long tables, 3 feet 

 by 12. These are covered with different colored tiles, imitating mud, 

 sand, gravel, sea- weed, black and white tiles, as well as red, yellow, blue, 

 green, violet, to get all possible variety of background. A space at 

 each end is covered with a glass plate, allowing the light to come from 

 underneath, thus enabling the observer to examine larger specimens 

 from the underside, without disturbing them when fully expanded. Two 

 shorter and narrower tables, 18 inches by 7 feet, are placed half way be- 

 tween these central tables and the southern face of the building. These 

 tables are intended for larger aquaria or dishes, and are covered with 

 common marble slabs. There is a blank wall on the south side, the whole 

 of which is occupied by closets and shelves for storing glass jars, reagents, 

 bottles, dishes, &c. A space is devoted to books. The basement is used 

 for the storage of alcoholic specimens, dredges, trawls, and other simi- 

 lar appliances. In the attic there is a large tank for salt water, and 

 another for fresh. The rest of the attic will be eventually devoted to 

 photographic rooms and room for an artist. The laboratory is supplied 

 with salt water by a small steam pump, driven by a vertical boiler of 5 

 horse-power. This is kept going the whole time, day and night, the 

 overflow of the tank being carried off by a large pipe. The water is 

 taken some distance from the laboratory, and drawn up at a horizontal 

 distance of 60 feet from the shore in a depth of some 4 fathoms, the end 

 of the section pipe standing up vertically from the ground a height of 

 5 feet, and terminating in an elbow to prevent its becoming choked. 

 The water is led through iron pipes coated inside with enamel. From 

 the tanks the salt water is distributed in pipes extending in a double 

 row over the central tables, over the long narrow tables for aquaria, 

 and along the whole length of the glass shelves on the south wall. 



