At last he found some time to spare. A sailor was left to trudge a look-out; one at the helm made two, one on the royal yard made three. The cook was the fourth, and the 'boy' was left to stand-by. Captain Parry followed the mate into the cabin, and, whilst Blundell went into his berth for the chart of the Atlantic, the captain stood looking about him and thinking. She had sat there, or there, he thought, at table. It was so recent, the very fragrance of her might be found in the atmosphere. How often had her feet trodden those steps? He saw her, in imagination, reading; she pored upon some volume, under that golden globe, with her hair illuminated; he thought of her agony of heart when she rushed on deck at the sound of firearms, and saw her father, the captain, and mate lying dead, and knew that she was alone with a crew of murderers.
'This is how Captain Barrington hopes we'll work it, sir,' said Blundell, coming out of Captain Glew's berth, and putting a chart upon the table.
He also produced a pair of compasses and a nautical instrument for measuring distances. He pulled a paper, covered with calculations, from his pocket, and placed it by his side.
'This will be it, I think, sir,' said Blundell, sticking a leg of the compass into the chart; 'where the point of this leg is we were when we parted company with the Alfred. We allow the boat a start of thirty-six hours, remembering always that our weather will have been hers.'
'Quite so!' exclaimed Captain Parry, devouring every word.
'I am now heading,' continued the mate, with a glance at the paper, 'to arrive at this point.' Here he put the pencil end of the compasses upon the chart. 'When we arrive there, our navigation will be this.'
He now, with great care, and constant references to the paper of figures, together with a frequent use of the nautical instruments for measuring distances, described a number of circles. These circles lay one within another, and when completed they might be likened to a cone-shaped spring, or to a corkscrew looked at vertically.
'You will perceive, Captain Parry,' said the mate, 'that the distance between each circle is the same. How far can a man see from the schooner's royal yard? Well, Captain Barrington would not allow that he should be able to see so small an object as a boat, even with a good telescope, at a greater distance than thirteen miles. Thirteen miles to port and thirteen to starboard. Each circle, therefore, is twenty-six miles wide.'
'If the boat is afloat,' exclaimed Captain Parry, viewing the discs with admiration full of hope, 'she must positively be within one of these circles?'
'Unless she has taken a breeze and blown clear, or means to come running into the inner whilst we're steering our dead best for the outer circles.'