We had arranged to start at daybreak on the following morning; but as we pulled off to the cutter we remarked that there was a nice little breeze blowing from the westward, and as the evening was beautifully fine and clear, with the promise of a brilliant starlight when the night should have fully set in, the idea occurred to us both that we might just as well be getting on down Channel at once, as be lying at anchor all night.
Accordingly, as soon as we got on board, we loosed and set our canvas, hove up our anchor, and in half an hour afterwards were slipping through the opening in the Portland Breakwater.
In little more than half an hour after that we were clear of the dreaded Bill, when, noticing that a small drain of flood-tide was still making, we hauled our wind on the port tack, and stood in towards Bridport for an hour; then tacked again, and stood out towards mid-Channel, so as to obtain the full benefit of the ebb-tide, which by this time had begun to make.
By “six bells,” or seven o’clock, on the following morning we were abreast the Start, about six miles distant. We stood on until eight o’clock, when we tacked again towards the land, having now a flood-tide against us, and had breakfast.
By noon we were in Plymouth Sound, when we made a short leg to the southward until we could weather Rame Head; then went about once more, stretched across Whitesand Bay until the ebb-tide began to make again, and then again hove about and stood to the southward and westward, on the starboard tack.
At six o’clock that evening we passed the Lizard lighthouse, distant two and a half miles, and here we took our departure.
For the benefit of those who may be ignorant of the meaning of this expression, I may as well explain that the commander of a vessel takes his departure from the last well-known point of land he expects to see before launching into mid-ocean, by noting, as accurately as he possibly can, its compass-bearing and distance from his ship at a particular hour.
With these data he is enabled to lay down upon his chart the exact position of his ship at that hour, and from this spot the skip’s reckoning commences. The courses she steers, and the number of knots or nautical miles (sixty of which are equal to sixty-nine and a half English miles) she sails every hour, together with certain other items of information, such as the direction of the wind, the direction and speed of the currents, if any, which she passes through, and the state of the weather, the lee-way the ship makes, etc., etc., are all entered in the log-book; and at noon every day, by means of certain simple calculations, the ship’s position is ascertained from these particulars.
The entering of all these particulars in the log-book is termed keeping the dead reckoning, and the working out of the calculations just referred to is called working up the day’s work.
This, however, only gives the ship’s position approximately, because it is difficult to judge accurately of the amount of lee-way which a ship makes, and it is not at all times easy to detect the presence of currents, both of which produce a certain amount of deviation from the apparent course of the ship.