[59] FISHERIES OF THE UNITED STATES. 1213 



Clark's hatching- jar— Continued. 



ing at the bottom, passing upward through the eggs and out 

 at the top. Height, 16 inches ; diameter, 6 inches. Invented 

 by Frank IS". Clark, of Korthville, Mich. 57,187. Presented 

 by Frank N. Clark. Formerly extensively used for hatching 

 eggs of the whitefish. 



Clark hatching-jar. (Intermediate form.) 



A cylindrical jar of glass, with a metal rim, having a spout on one 

 side, through which the surplus water escapes. The water is 

 introduced at the bottom through a tin tube with a funnel 

 shaped opening, and passes upward through the eggs on its 

 way to the outflow spout. Height, 16 inches ; diameter, 6 

 inches. Designed by Frank ST. Clark, Northville, Mich. 

 57,188. Presented by Frank N. Clark. Extensively employed 

 for hatching eggs of the whitefish at the Fish Commission 

 hatching station at Northville, Mich. 



Clark hatching- jar. (New style.) 



A cylindrical jar of glass, with a metal rim, having a spout at one 

 side, from which the surplus water escapes. The bottom of the 

 jar is provided with a metal cone corresponding with the fun- 

 nel-shaped end of the supply tube, which is prevented from 

 coming in contact with it by means of slight projections on 

 its inner surface. Height, 18 inches; diameter, 6 inches. De- 

 signed by Frank N. Clark, North ville, Mich. 57,189. Pre- 

 sented by Frank N. Clark. This jar is coming into favor for 

 hatching eggs of the whitefish, and is now used extensively 

 at the Northville hatchery. 



Shad-hatching cone. 



With screen at the bottom. Devised by Charles F. Bell and Fred. 

 Mather. 26,995. U. S. Fish Commission. 



Ferguson's improved conical hatcher. 



With removable top, used to prevent splashing ; also arrangement 

 for easily removing bottom screen. Valve used when bottom 

 screen is to be removed or eggs and young fish to be transferred. 

 Furnished also with hook for lifting vessel from frame. T. B. 

 Ferguson. U. S. Fish Commission. 



Section of V-shaped hatching-trough. 



A simple trough, with false sides sloping downward from the top 

 toward the center, leaving the space of one-eighth of an inch, 

 covered with wire cloth, between their lower edges. The upper 

 part of the trough is surrounded by perforated tin, through 

 which the water passes into a sluiceway and thence to the 



