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tray. Each hatching tray near its lower end had a leaden 
overflow pipe, which projected over the tray next below it. A 
wooden cover fitted the top of each tray, with a hole to receive 
the water flowing down from above. 
The cask, thirty-three inches high, was raised on empty 
boxes, and contained thirty-six gallons. The supply tank 
(inside) sixteen and a quarter inches long, six and a half inches 
deep, and seven inches wide. Each hatching tray (inside 
measure) eighteen inches long, six inches deep, and three and 
a half inches high, the water standing two inches deep, above 
this level the overflow pipe acting. 
For the purpose of charring the inside of the casks they 
were filled with shavings, which were then set alight, the fear 
being not that the inside would be too much burnt, but more 
likely too little. As soon as sufficiently burnt the cask was 
inverted, to put out the fire, and when cold the inside was well 
scraped, and then washed out with water in which a little soda 
had been dissolved, and finally scrubbed with a birch broom. 
As any remains of paraffin would be deleterious to the young 
fish, it is best to let the cask stand full of water for some time 
before using it. 
The insides of the supply tank and hatching trays were also 
burnt, while the outsides and covers were painted with Bruns- 
wick black. The water supply was from a contiguous pump, 
which doubtless, owing to having been mostly unused, soon got 
out of order, and gave a considerable amount of trouble, as I 
shall have to detail. The whole apparatus, raised on empty 
boxes, was placed in an unused coach-house, so also was the 
extra water cask from which the reservoir was replenished, in 
order that the newly added water might be of about the same 
temperature as that going to the hatching trays. 
The water having been obtained from the pump in buckets, 
it was easy to calculate the amount used daily, because every 
bucket-full equalled the capacity of two hatching trays, or was 
equivalent to the water passing once through them, so twenty- 
four buckets-full in twenty-four hours was equal to the water 
going twenty-four times over the eggs. Although it is doubtless 
