1046 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [10] 



strument, by using a tin tube with a wide flange or rim at the bottom, 

 conical in shape to conform to the lower section of the above-mentioned 

 double cone over which it was set, the cone being inverted so that the 

 strips of tin serving as feet when used with the other jar, would raise 

 the tube to allow the water to escape uniformly from the outer edge of 

 its flange or rim. 



Mr. Bower also fitted up a rectangular box or tank for an incu- 

 bator, so constructed that the eggs rise from the center and settle 

 down the outside, exactly reversing the jar movement. It is 12 

 inches wide, 13 deep, and 30 long, although its length might be ex- 

 tended indefinitely without disturbing or changing its operation. It is 

 divided into upper and lower sections, and, as with the jars, a water- 

 pressure or head is required. The desired movement of the eggs is ob- 

 tained by introducing the water into the lower section, whence it is 

 admitted to the upper section, which is the egg-chamber, through a six- 

 teenth-inch crevice running lengthwise of the box. From either side 

 and 6 inches from the top the partition whicli divides the box into two 

 sections slants downward to converge the eggs to the center where the 

 current forced through the crevice carries them uji again to settle back, 

 fountain-like, as before. Overflows with wire gates are provided at in- 

 tervals around the top of the box. This apparatus was not tried until 

 the eggs had already begun hatching, so that no opportunity to correct 

 its faults by a practical test was given. It worked very well, however, 

 although after trying it we were well satisfied that it should be given 

 greater depth, less width, and a greater head of water. Doubtless a 

 little more experimenting with this or a similar device will produce an 

 incubator that will be entirely satisfactory, as the principles by which 

 the water currents are obtained and controlled are correct ; while it 

 would have the merit of being easily operated, and furnishing capacity 

 for many millions of eggs at a merely nominal cost. 



Spring water alone is used for hatching purposes at this station, and 

 where it first issues from the earth varies but little from a temperature 

 of 47°. In consequence of the very moderate weather which prevailed 

 the past winter, our arrangements for securiug a lower temperature — 

 continued exposure to the air before reaching the hatchery — were of 

 little avail. The eggs, therefore, progressed very rapidly from the first 

 until all were hatched. 



The first orders for whitefish eggs to be filled were from Herr von 

 Behr and G. Ebrecht, Germany. The eggs were packed in separate 

 cases and started on their journey December 19, consigned to Fred. 

 Mather, Newark, X. J., whence they were reshipped to destination. 

 These and subsequent lots were prepared for sliipping substantially as 

 follows: First, a sufiicient number of trays of canton flannel are made, 

 also a substantial case for the same, of the proper size to allow 4 to 6 

 inches space all around for the packing material. The trays are then 

 anchored in a tank of water. A quantity of eggs are transferred from 



