240 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



their breeding. In all probability, therefore, provided that the chem- 

 ical constituents of the water were not such as to prove injurious, self- 

 sustaining oyster beds might be established in the waters flowing from 

 this spring, but their quality would not be sufficiently good to warrant 

 the attempt. 



If, however, this water were conducted into shallow ponds the evap- 

 oration would tend to raise the density. The evaporation at Salt Lake 

 City is about 75 inches per annum and the rainfall about 50 inches, so 

 that the net loss in fresh water is about 2 feet per year. A pond 2i 

 feet deep and without an outlet would by solar evaporation alone have 

 its density raised to within the desired limits in less than two years, 

 provided sufficient water from the spring be introduced from time to 

 time to replace that lost by evaporation. If no water be allowed to 

 escape from the pond save by evaporation, there will be speedily repro- 

 duced in miniature the conditions prevailing in Great Salt Lake and the 

 density would soon rise to a degree fatal to the oyster. After the pond 

 has reached the desired salinity, however, it may be maintained within 

 the proper limits by regulation of the intake and outlet sluices, the 

 inflowing stream of lower density tending to reduce the salinity of 

 the pond by replacing the denser water which flows from the outlet. 

 By a nice adjustment of the influent and effluent streams it would be 

 possible to regulate the density within comparatively narrow limits with 

 a minimum of personal attention on the part of the operator. Two 

 conditions are imposed by the problem : {a) The inflow must equal the 

 amount of water lost by evaporation, plus the quantity flowing out of 

 the pond, minus that which is gained from the rainfall in the pond; (Z>) 

 the smaller amount of dense water flowing out must contain the same 

 amount of salt as the larger amount of less dense water flowing in. 



GREAT SALT LAKE. 



Great Salt Lake is situated in the northwestern part of Utah, west 

 of the Wasatch Mountains, being embraced within the limits of Box 

 Elder, Weber, Salt Lake, and Toelle counties. Its length is about 80 

 miles, lying in a northwest-southeast direction, and its greatest width 

 is about 35 miles. In 1869 it had, according to King's survey, an area 

 of 2,170 square miles, this being the maximum area within historic 

 times. At the present time it has decreased to approximately the j 

 dimensions shown on the Stansbury map of 1850, when it had an area j 

 of about 1,750 square miles, 20 per cent less than in 1869. Its maximum 

 depth, according to Stansbury, was 36 feet; and the King survey, made I 

 at the time of highest water within recent years, reports a depth of 

 49 feet. The shrinkage since 1869 has been approximately 10 feet, so | 

 that the maximum depth is not far from 38 or 39 feet at j)resent. The j 

 deepest water is west of the Promontory, the water east of that penin- 

 sula and Antelope Island being comparatively shoal and graduallyj 

 becoming shoaler by the deposit of silt from the rivers. 



The principal islands are Fremont and Antelope, in line between tbel 



