“Captain Gordon, has the first master given the quartermaster the course yet?” asked Mr. Lowington, when the steamer had disappeared among the islands of the bay.

“No, sir; but Mr. Fluxion told him to make it east-north-east.”

“Very well; but the masters should do this duty,” added Mr. Lowington, as he directed the instructor in mathematics to require the masters, to whom belonged the navigation of the ship, to indicate the course.

William Foster was called, and sent into the after cabin with his associates, to obtain the necessary sailing directions.  The masters had been furnished with a supply of charts, which they had studied daily, as they were instructed in the theory of laying down the ship’s course.  Foster unrolled the large chart of the North Atlantic Ocean upon the dinner table, and with parallel ruler, pencil, and compasses, proceeded to perform his duty.

“We want to go just south of Cape Sable,” said he, placing his pencil point on that part of the chart.

“How far south of it?” asked Harry Martyn.

“Say twenty nautical miles.”

The first master dotted the point twenty miles south of Cape Sable, which is the southern point of Nova Scotia, and also the ship’s position, with his pencil.  He then placed one edge of the parallel ruler on both of these points, thus connecting them with a straight line.

A parallel ruler consists of two smaller rulers, each an inch in width and a foot in length, connected together by two flat pieces of brass, riveted into each ruler, acting as a kind of hinge.  The parts, when separated, are always parallel to each other.

Foster placed the edge of the ruler on the two points made with the pencil, one indicating the ship’s present position, the other the position she was to obtain after sailing two or three days.  Putting the fingers of his left hand on the brass knob of the ruler, by which the parts are moved, he pressed down and held its upper half, joining the two points, firmly in its place.  With the fingers of the right hand he moved the lower half down, which, in its turn, he kept firmly in place, while he slipped the upper half over the paper, thus preserving the direction between the points.  By this process the parallel ruler could be moved all over the chart without losing the course from one point to the other.

On every chart there are one or more diagrams of the compass, with lines diverging from a centre, representing all the points.  The parallel ruler is worked over the chart to one of these diagrams, where the direction to which it has been set nearly or exactly coincides with one of the lines representing a point of the compass.

The first master of the Young America worked the ruler down to a diagram, and found that it coincided with the line indicating east by north; or one point north of east.

“That’s the course,” said Thomas Ellis, the third master—­“east by north.”