122 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



transport the diatoms within reach of the sedentary oysters. In the 

 open waters these currents were furnished by the tides, but in the 

 pond there were only feeble currents produced by the winds and local 

 differences in the temperature of the water. 



To supply the necessary currents a canal faced with sheet piling was 

 constructed along one side of the pond and communicating with it at 

 both ends. This canal is about 150 feet long and *J feet wide, and is 

 provided wdth 16 wooden floats or trays 8 feet 8 inches square and 4 

 inches deep inside. Kaeh float is capable of holding about three bar- 

 rels of oysters in a single layer packed nib up, and is hung by ropes 

 attached to small roller windlasses about 6 inches above the bottom. 

 A current through the canal is produced by a propeller at the inlet 

 driven by a gasoline engine connected l)y rubber belting. During the 

 first year power was supplied by a windmill, but it was found that 

 much power was lost, owing to the frequency of calms and winds too 

 light to carry the load, and the more reliable motor was substituted. 



The method of operating the claire is briefly as follows: Before the 

 opening of the oyster season a supply of commercial fertilizer is 

 applied in the shallow water around the edges of the pond, whence it 

 gradually reaches the surrounding water, stimulating a vigorous 

 growth of oyster food. Poor, unsalable oysters are then placed on 

 the floats in the canal and, the propeller being set in motion, a current 

 of about 1 mile per hour is maintained, carrying over the oysters a 

 constant supply of diatoms from the rich store contained in the pond 

 at large. It was found that by this means the oysters in the canal 

 fattened quickly and uniformly, an extremely low proportion of l)lanks 

 or watery oysters being found. 



Owing to the exigencies of experimental work, the utmost capacity 

 of the claire in fattening oj^sters has not yet been determined, but the 

 fact that one lot was raised from a very poor to first-class condition 

 in eight days indicates that it will be considerable when the proper 

 arrangement is discovered. With the present canal capacity, which 

 could probably be considerably increased to advantage, a maintenance 

 of this rate would give a capacity of about 175 barrels per month, or 

 1,400 barrels during the season of eight months, from a 2-acre farm. 

 During the past season two difficulties which militated against a true 

 test of the capacities of the ponds were encountered: Occasionally a 

 ver}^ slight marshy taste would be noticeable in the oysters, and at 

 such times no shipments were made, for fear of injuring the demand. 

 It has been learned that this can be overcome hy the application of 

 lime to the water at the end of the canal. The other difliculty is that 

 in wet seasons with few high tides the water in the pond becomes too 

 fresh and the oysters rather too insipid to bring the highest price in 

 the market. A plan is now under consideration and will be put into 

 operation during the ensuing season which it is thought will obviate 

 this. Under the best conditions, oysters placed in the pond in an 



