Part 8 (1/2)
Mr Smellie--who was at all times an abstemious man--contented himself with a couple of gla.s.ses of wine after dinner, and, the moment that the conversation took a general turn, rose from the table, excusing himself upon the plea that he had several matters to attend to in connection with the expedition. As he rose he caught my eye and beckoned me to follow him, which I did after duly making my bow to the company.
When we reached the deck the fog was so thick that it was as much as we could do to see the length of the s.h.i.+p.
”Just as I expected,” remarked my companion. ”How are we to find the creek in such weather as this, Mr Hawkesley?”
”I am sure I don't know, sir,” I replied, looking round me in bewilderment. ”I suppose the expedition will have to be postponed until it clears a bit.”
”Not if I can prevent it,” said he with energy. ”Although,” he added, a little doubtfully, ”it certainly _is very_ thick, and with the slightest deviation from our course we should be irretrievably lost. Whereaway do you suppose the creek to be?”
”Oh, somewhere in that direction!” said I, pointing over the starboard quarter.
”You are wrong,” remarked my companion, looking into the binnacle. ”The tide is slackening, whilst the land-breeze is freshening; so that the s.h.i.+p has swung with her head to the eastward, and the direction in which you pointed leads straight out to sea. Now, if you want to learn a good useful lesson--one which may prove of the utmost value to you in after- life--come below with me to the master, and between us we will show you how to find that creek in the fog.”
”Thank you,” said I, ”I shall be very glad to learn. Why, you do not even know its compa.s.s-bearing.”
”No,” said Smellie, ”but we will soon find it out.” With that we descended to the master's cabin, where we found the owner in his s.h.i.+rt- sleeves and with a pipe in his mouth, poring over a chart of the coast on which was shown the mouth of the river only, its inland course being shown by two dotted lines, indicating that the portion thus marked had never been properly surveyed. He was busily engaged as we entered laying down in pencil upon this chart certain corrections and remarks with reference to the ebb and flow of the tidal current.
”Good evening, gentlemen!” said he as we entered. ”Well, Mr Smellie, so you are going to lead the attack upon the slavers to-night, I hear.”
”Yes,” said Smellie, unconsciously straightening himself up, ”yes, if this fog does not baffle us. And in order that it may not, I have come to invoke your a.s.sistance, Mr Mildmay.”
”All right, sir!” said old Mildmay. ”I expected you; I was waiting for you, sir.”
”That's all right,” said the second lieutenant. ”Now, Mildmay,” bending over the chart, ”whereabouts is the _Daphne_?”
”_There_ she is,” replied the master, placing the point of his pencil carefully down on the chart and twisting it round so as to produce a black mark.
”Very good,” a.s.sented Smellie. ”Now, look here, Mr Hawkesley, this is where your lesson begins.” And he produced the sketch-chart he had made that afternoon and spread it out on the table.
”You will see from this sketch,” he proceeded, ”that the _Daphne_ bore exactly north-north-west from the tree in which we were perched when I made it. Which is equivalent to saying that the tree bears south-south- east from the _Daphne_; is it not?”
I a.s.sented.
”Very well, then,” continued Smellie. ”Be so good, Mr Mildmay, as to draw a line south-south-east from that pencil-mark which represents the _Daphne_ on your chart.”
The master took his parallel ruler and did so.
”So far, so good,” resumed the second lieutenant. ”Now my sketch shows that the outer extremity of Shark Point bore from the tree north-west west. In other words, the tree bears from Shark Point south-east east. Lay off that bearing, Mildmay, if you please.”
”Very good,” he continued, when this second line had been drawn. ”Now it is evident that the point where these two lines intersect must be the position of the tree. But, as a check upon these two bearings I took a third to that sharp projecting point at the mouth of Banana Creek,”
indicating with the pencil on the chart the point in question. ”That point bears north-west by north; consequently the tree bears from it south-east by south. Mark that off also, Mildmay, if you please.”
The master did so, and the three lines were found to intersect each other at exactly the same point. ”Capital!” exclaimed Smellie, in high good-humour. ”That satisfactorily establishes the exact position of the tree. Now for the next step. The slave fleet bears north-west west from the tree; and the western entrance to the creek (that by which we shall advance to the attack to-night) bears exactly north-west from the same point. Let us lay down these two bearings on the chart--thus. Now it is evident that the slave fleet and the entrance to the creek are situate _somewhere or other_ on these two lines; the question is--_where_? I will show you how I ascertained those two very important bits of information if you will step to my cabin and bring me the telescope which you will find hanging against the bulkhead.”
Intensely interested in this valuable practical lesson in surveying I hurried away to do his bidding, and speedily returned with the gla.s.s, a small but very powerful instrument, which I had often greatly admired.
Taking the telescope from my hand he drew it open and directed my attention to a long series of neat little numbered lines scratched on the polished bra.s.s tube.
”You see these scratches?” he said. ”Very well; now I will explain to you what they are. When I was a mids.h.i.+pman it was my good fortune to be engaged for a time on certain surveying work, during which I acquired a tolerably clear insight of the science. And after the work was over and done with, it occurred to me that my knowledge might be of the greatest use in cases similar to the present. Now I may tell you, by way of explanation, that surveying consists, broadly, in the measurement of angles and lines. The angles are, as you have already seen, very easily taken by means of a pocket-compa.s.s; but the measurement of the lines bothered me very considerably for a long time. Of course you can measure a line with perfect accuracy by means of a surveyor's chain, but I wanted something which, if not quite so accurate as that, would be sufficiently correct, while not occupying more than a few seconds in the operation of measurement. So I set to work and trained myself to judge distances by the eye alone; and by constant diligent practice I acquired quite a surprising amount of proficiency. And let me say here, I would very strongly recommend you and every young officer to practise the same thing; you will be surprised when you discover in how many unexpected ways it will be found useful. Well, I managed to do a great deal of serviceable work even in this rough-and-ready way; but after a time I grew dissatisfied with it--I wanted some means of measuring which should be just as rapid but a great deal more accurate. I thought the matter over for a long time, and at last hit upon the idea of turning the telescope to account. The way I did it was this. You have, of course, found that if you look through your telescope at an object, say, half a mile away, and then direct the instrument to another object, say, four miles off, you have to alter the focus of the gla.s.s before you can see the second object distinctly. It was this peculiarity which I pressed into my service as a means of measuring distances. My first step was to secure a small, handy, but first-rate telescope--the best I could procure for money; and, provided with this, I commenced operations by looking through it at objects, the exact distances of which from me I knew. I focused the gla.s.s upon them carefully, and then made a little scratch on the tube showing how far it had been necessary to draw it out in order to see the object distinctly; and then I marked the scratch with the distance of the object. You see,” pointing to the tube, ”I have a regular scale of distances here, from one hundred yards up to ten miles; and these scratches, let me tell you, represent the expenditure of a vast amount of time and labour. But they are worth it all. For instance, I want to ascertain the distance of an object. I direct the telescope toward it, focus the instrument carefully, and find that I can see it most clearly when the tube is drawn out to, say, this distance,”