NOTES ON A NEW HATCHING JAR 



BY FRANK N. CLAEK, XORTHVILLE, :\I1CII. 



Of the \arious open top jars heretofore invented, Ijut little 

 atte]Uion or consideration has been given to the formation ni .i 

 jar so shaped that in operation it would be automatic to tlic ex- 

 tent of separating the live from the dead eggs. Believing tht' 

 construction of such a jar to be entirely feasible and within the 

 limits of probal)lc success, experiments Avere undertaken, the 

 final res\dt of which has been the successful demonstration of a 

 new form to 1)0 designated and known as the Clark Hatcbino- 

 Jar. 



In l)riefly describing this improved forni, it would be stated 

 that the bottom is identical with that of the Downing jar, and 

 also it has the same outline for about one-third the distance up 

 the sides. It is then gradually drawn in or made smaller, until 

 it ends iu a straight and comparatively narrow neck some four 

 inches in length. On one side of this is the glass overflow, which 

 is nearly twice as long as that on most forms. In the Clark jar 

 one of the objects sought has been to have it so shaped that the 

 currents of water would cause the good eggs as they came to the 

 top, to be thrown inward and downward toward the center, while 

 the lighter and poorer eggs would instead go to the surface, 

 where they would be easily removed, or else would run off of 

 their own accord. In other words, the idea was to perfect a jar 

 for the handling of whitefish eggs which would be as nearly auto- 

 matic in this respect as possible. The objection to the usual 

 form of C^hase or Downing jar has been the requirement of a 

 considerable amount of labor for drawing off dead eggs, and 

 also there is always the chance that quite a number of good eggs 

 are unintentionally drawn out during the operation of using the 

 siphon. However, the necessity of thus daily attending to tlv-^ 

 jars has never Ijeen questioned, for if not drawn off there was 

 great danger of the fungus settling and mixing with the good 

 eggs in the lower portions of the jar, thereby causing serious 

 loss, and also inconvenience in handling. With these disadvan- 

 tages in mind, it was set about to devise a new" jar which had p 

 current with a tendency to lift out the larger inferior eggs, or 



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