MIDDLETHIRD HATCHING-HOUSE. 



131 



meter was inserted in this leg to show the temperature of the 

 water. 



A frame was made as a stand for the five rearing-boxes, and a 

 waste-spout was led along the outlet ends ; a supply-spout started 

 from the upright of the E-trough, and fed all the rearing-boxes 

 (Fig. 81). This feeding-spout was made much larger than necessary 

 for conveying the water, so that the water might be dead opposite 

 the little sluices that supplied the rearing-boxes ; and it was 



FIG. 81 scale ^. 



thought that the sluices could be set against a head of say 4 inches 

 of water, and run a constant flow ; but in practice it was not so. 

 I therefore filled the grooves of the sluices with a 4 -inch piece of 

 wood (Fig. 82), and made them into overflow sluices ; the water 

 then either divided equally over all, 

 or was shut off any desired boxes 

 entire by shutting a sluice above 

 the 4-inch piece (Fig. 83). This is 

 a sufficient power of regulation FIQ. 83 scale ,v 

 even in the largest works, for it is not possible to feed more than a 

 small number of boxes from one spout, on account of the expense of 

 a very long level. This expense is due not only to the long and 

 expensive foundations required, but to the necessity of increasing 



FIG. 82 scale ^\. 



