[5] PROPAGATION OF WHITEFISH AT NORTHVILLE, MICH. 557 
results of which proved ‘quite satisfactory. An open trough, resting on 
stilts driven just beneath the surface of the water and drawing from the 
upper or spring-fed part of the pond, was laid the entire length of the 
pond. This being the only exit allowed for the discharge of the super- 
fluous water, the entire waste was thus drawn from the immediate 
vicinity of the springs. 
The dimensions of the ice-water pond were then increased to 150 feet 
in length by 18 feet in width, with its boundary maintained by a wall 
of masonry backed up on one side of the pond by the natural elevation 
of the ground, on the other by a layer of clay of sufficient thickness to 
prevent leakage. The trunk from the spring pond discharges into an 
open, Shallow trough, which carries the water to the farther end of the 
ice-water pond for the purpose of cooling as much as possible by ex- 
posure to the air while in transit, the two conductors for the tank room 
tapping the opposite end of the pond. The additional precautionary 
measures adopted for cooling the water were thought to be sufficient, 
but, as a result of the increased work of the season, the demand of the 
hatchery required fully one-half of the product of the spring, and, not- 
withstanding the unusual severity of the winter, it was found necessary 
at times to use considerable quantities of ice in the tank room to keep 
the temperature of the water down to the desired point. The cooling- 
pond rendered efficient service, but did not fully meet anticipations. 
The repairs to the hatchery included a new roof and new floors for 
the hatching and tank rooms. A small temporary apartment was 
arranged in one corner of the hatching room adjoining the office, which 
was occupied as a sleeping room by one of the employés during the 
hatching season. This precaution was adopted upon the supposition 
that the sleep of the occupant would be interrupted as quickly by the 
cessation of the noisy monotony of running water in the hatching room 
as by the sudden intrusion of noise under ordinary circumstances. 
One double row of hatching boxes were removed, and replaced by a 
tier of tanks for feeding the hatching jars. These tanks, three in num- 
ber, are placed one above the other, and consequently occupy but little 
more floor room than a single row of hatch boxes; they are uniform in 
size, viz, 40 feet long by 15 inches wide and 14 inches deep, the top one 
being fitted with 50 and the middle one with 56 No. 8 faucets, or 106 
altogether. The jars rest on narrow shelves placed crosswise of the 
tanks, one shelf sufficing for two jars, one at either end, the water 
entering the top tank feeding the upper rows of jars, which, in turn, 
supply the middle tank, from which the lower rows of jars are fed, the 
water from these emptying into the bottom tank, which, at present, 
serves only as a conductor for the waste water. The five rows of hatch- 
ing boxes remaining were thoroughly examined, and given the needed 
repairs, in the way of caulking &c. Some of the wire trays were 
repaired, while others were supplied with new screens entire, and all 
were given a coat of asphaltum varnish. The picking trough was 
lengthened to 50 feet. 
