The places where the river was certainly (i.e. except 4th) open yesterday were all only five feet or less in depth, according to my map, and all except 8th at bends or else below the mouth of a brook . . .

  Hence, I should say, if you wish to ascertain where the river is five feet, or less than five feet, deep in Concord, wait till it is open for not more than half a dozen rods below Nut Meadow . . .