Alec, all this time, was getting ready for his part of the work. He took a galvanized bucket that belonged on the _Osprey_ and lowered it overboard for a few moments so it would take on the temperature of the Bay. Then he lifted it aboard, brimming with water, and set it in the shade. Elsa thrust the salinometer and testing tube into the bucket to cool. Then Alec attached his hose to his lift pump, and carefully lowering the hose to a point within a few inches of the bottom, pumped his own bucket, which had also been cooling in the waves, full of water. It was the sample from the bottom, in which the oysters actually lie, that he wanted to test.
Elsa drew her tube and salinometer out of the cooling bucket, and Alec filled the tube with water from his own bucket. Elsa lowered the salinometer into it and put the tube in the shade. Then she held the bolting-cloth net over a tub, while Alec slowly emptied his bucket of water from the bottom into it. The bucket contained ten quarts and Alec had it brimming full. Gradually the water filtered through the net into the tub, leaving on the inside of the net whatever sediment had been in the water. In this sediment Alec expected to find the oyster larvæ. Ten times they did this, until they had strained one hundred quarts of water through the net. From time to time Alec threw the filtered water overboard. Finally the net was lifted clear of the tub and the last of the water allowed to filter through it. While Elsa held the net up, Alec washed the sediment from the sides down into the tip of the net, with water dipped from the tub. When the filtering process was fully completed, and the sediment all concentrated in the tip of the net, Alec carefully untied the draw string, opening the end of the net, and, using his large rubber bulb pipette, washed the sediment into one of his wide-mouthed settling bottles.
Now Elsa turned her attention to her salinometer. It was intended to register the density or degree of saltiness of the water. Alec could hardly restrain his impatience, so eager was he to see what the instrument would tell.
"You know, Elsa," he said, "that sometimes the best seed grounds are in waters of so low a density as to be entirely unsuitable for fattening or even growing oysters. I've been thinking about that a whole lot, for most of the oysters we dredged on the _Bertha B_ this year were very poor. They hadn't fattened a bit. Captain Bagley said he never had caught any good oysters in that bed. I've just been wondering if the water wasn't of the proper density. Why, those oysters would have been worth a whole lot more if they had been fat."