The common log consists of a triangular wooden float, a line marked with knots at equal distances apart, and a reel. The float is thrown overboard, and the line allowed to run off the reel for a certain number of seconds. The proportions of the distances between knots are such that the number of them run off in the given time is the number of miles an hour which the vessel is making. "We shall be safe in saying that we are doing an even nineteen knots," said the Captain. "We ought to strike the easterly edge of the Newfoundland Banks a little before four o'clock, in longitude 48° 30' west and latitude 45° 40' north, and we ought to get a sounding there of fifty-four to fifty-eight fathoms. Mr. Parker, you will get the sounding-machine ready to take a cast at five minutes of four o'clock." "Ay, ay, sir," answered the third officer. The sounding-machine consists of a heavy lead on the end of a very long piano-wire wound round a cylinder. With this a sounding can be taken while a vessel is going ahead at the rate of twelve or fifteen knots, while with an old-fashioned deep-sea lead line it is necessary to stop. An indicator on the side of the sounding-machine shows how many fathoms of wire are out, and there is a crank for winding it in. At five minutes of four the third officer took the sounding, and reported a depth of fifty-five fathoms. "Good," said the Captain, who was now in his room consulting the chart. "So far we know exactly where we are. We shall keep our present course. You will take another sounding at seven o'clock, when we should be fifty-seven miles west sou'west of this, and you should get thirty-three fathoms. How's the weather?" "Looks like fog before morning, sir." "Hum!" muttered Captain Jason Argo, through his clinched teeth, "I shall hold our present course at least till we clear the Banks. It's 150 miles across, as we are going, and I wish soundings taken every two hours till we are across, which will be in eight hours. You will pass the word to call me when the last sounding is to be taken." The third officer returned to the deck. At seven o'clock he made the sounding, as directed, and got a depth of thirty-two fathoms, which tallied closely enough with the Captain's calculations to show that they were correct. Steadily the _Golden Fleece_ ploughed her way westward across the comparatively shallow waters of the Grand Banks, and at midnight, the Captain having been called, the last cast of the lead showed eighty fathoms. "Good," said the Captain, turning his face against the damp rush of the heavy mist; "we shall run into 1500 fathoms now, and into the northerly limit of the Gulf Stream. On the whole, I think we'd better give our course an eighth more southing, and hold it at that till noon. Keep a bright lookout ahead, and keep your weather eye on the sky. If it breaks away, look sharp, and get the deviation from the first star that shows. I think we're in for a lot of thick weather."