Toward the upper end of the Carter farm the dike curved sharply inland till it joined the steep slope of their pasture lot. Here was a spacious cove, inclosed by the Carter's pasture lot on the south and west, by their dike on the east, and on the north by the channel of the creek. At the time the dike was built the channel had lain close in along the foot of the upland, but it had gradually moved out to a straight course as the cove filled up with sediment. Of this change the dike itself had been the main cause. Now the cove appeared at high water as a bay or lagoon; but very early in the ebb its whole surface was uncovered, and, except along the outermost edge, thin patches of salt grass were already beginning to appear.
To this spot the boys betook themselves, treading the way gingerly over the tenacious but slippery surface. Will pointed to a half barrel sunk level in the ooze. It was full to the brim with fine silt.
"What do you think of that?" inquired Will, mysteriously.
Ted racked his brain for a suitable reply. He could gather no clew to Will's purpose, so he remarked:
"Very nice, healthy looking mud, seems to me? Going to sell it for brown paint?"
"Paint!" exclaimed Will, scornfully. "But how long do you suppose that tub has been there?"
"Looks as if it had been there from the year one," replied Ted, still hopelessly adrift.
"I put it there just three weeks ago!" said Will, watching his brother's face.
"You did!" said Ted, blankly. Then a light dawned upon him. "But that's mighty quick work!" he continued. "You don't mean to tell me that all that mud was deposited by the tide in three weeks!"
"Every bit of it!" averred Will. "You see the Tantramar water is just loaded with silt. It has so much that the moment it stops to rest it throws down as much of the load as it can. When it gets moving, regularly under way, it has to pick it up again. But the longer it stops the more it throws down; and the slower it moves the less it picks up again. Inside the tub it is always slack water, so whatever falls there stays there. That's why the tub has filled up so quick. Nearly a foot and a half in three weeks! Why, Ted, a raise of a foot and a half along the outer slope of this cove, and we could dike in the whole cove. See?"