The Wonder Island Boys: The Mysteries of the Caverns Part 15

"It seems, then, that a man must be pretty well versed in the weather to be able to read the signs."

"That is a correct observation. The instrument in the hands of one who has had experience with its use is absolutely necessary; it is not a very satisfying device for those who do not take the time or trouble to read all the signs, and note all the indications."

As detailed in a preceding chapter, the hardened steel rod for the compa.s.s was brought out for the purpose of securing it in a little case, so that it might be utilized to give them the true north.

It was a difficult task to find a means of suspending it, for the reason that they had no tools which would make fine and carefully pivoted balances, but eventually this was done, and they were gratified to see the little rod or bar swing around and point north and south.

The work of arranging suitable closets for the various provisions and providing a miniature kitchen was the next thing in order. This occupied several days. Instead of taking the bedding in their house, it was decided that new mattresses should be made up from the barley, of which there was quite a quant.i.ty on hand.

One of the receptacles taken from the cave was a copper jar, which held five gallons of water. A top was made for this which could be sealed up, to hold a reserve supply of water. In addition two other vessels were also provided for the regular supply, and also fitted with covers, so that they had about ten gallons, an amount which was considered sufficient.

The matter of fuel was a more difficult one to solve, unless they intended to prepare most of the food before starting; but George insisted that the small stove should be put aboard, and about fifty pounds of the coal stowed away.

"How long do you think we should provision for?" was George's inquiry, as they were carrying the various things aboard.

Harry had no ideas on the subject, but the Professor ventured the opinion that at least two weeks' supply should be arranged for.

This conclusion rather startled the boys, who had not expected more than a few days' trip, and when they questioned him about his reasons for making the statement, he said: "Did you ever hear of the old lady who attended a special meeting of prayer for rain? She came with an umbrella, and the people laughed and chided her. The minister reproved them, saying: 'She, at least, has faith, which you have not.' We are going for two purposes: one is to learn something about the island we are on, and the other to rescue our companions if they can be found. We couldn't rescue them and let them starve."

Those words impressed them as nothing theretofore had, that the Professor believed they were really going to find their former shipmates, and that they would have stirring times before them.

Nothing so stimulates the actions of men, or boys, as the prospect of adventure. Their trip had a double meaning, and it is not venturing too much to say that their feelings were most tense during the entire period in which they were engaged at the task of fitting out the little ship.

At last the day was set for the departure. The cattle could take care of themselves. A tablet was prepared to be put up on their dwelling, stating who were the owners of the habitation, their present destination, and briefly relating the knowledge they possessed of the inhabitants of the island, a statement of the direction they had taken, and the kind of boat to which they trusted their destiny, and when they expected to return.

A copy of this was then carried to the pole on Observation Hill, and nailed to the mast, to replace the small tablet which had hitherto filled that place. They were to launch the boat for the start on the morrow.

That night a storm blew up from the west, as most of the winds had previously blown from that quarter during the past month. The storm was severe during the entire night, and abated somewhat in the forenoon, but it again increased in fury before noon and continued with more or less vigor all that day and during the night.

"I am afraid this storm will prevent us from starting for several days, on account of its widespread character. The sea for hundreds of miles has been subject to this monsoon, and we would have a very rough time until the sea quiets down."

The delay was a bitter thing for the boys. Expectation had run high.

Antic.i.p.ation doesn't mildly or easily brook waiting. They did not know what to do, or how to pa.s.s the time in the interim. It was such a new and trying condition for them.

The Professor noticed how they chafed under the restraint, but apparently took no heed of it. However, he encouraged them in every effort they made to divert themselves and to occupy their minds during the waiting period.

During one of these spells which come on all more or less during such trying hours, George could not hold in any longer, but broke out impatiently: "What is the use of waiting any longer? The storm may keep up for a week."

"Then do you think we had better venture a start under these conditions?"

George thought a while. He appreciated the risk. Harry, too, was anxious and nervous, and expressed a willingness to take the risk.

"Let me put another side to the question," said the Professor. "We are perfectly safe here. You take no risks by remaining. You have in the cave treasure that will make you millionaires. You cannot afford to take any risks. If we knew something of the conditions on the island, and had a certain knowledge that our comrades were in danger, the considerations I have named should not deter us from starting. But with all these things in the dark, and with the monsoons likely to break out again at any time, the question is whether we can afford to risk the safety of the enterprise because of impatience at delay."

"Yes," answered Harry. "I have thought of these things, and I feel that the Professor's advice should be followed."

The boys were particularly surprised that he should refer to the money in the cave as a reason why they should consider their actions in the matter. It was so unlike him to refer to any sordid considerations as a reason for not performing a great duty.

"I would also remind you that one of the greatest boons ever given to the great investigators of the world came through delays. Time is a wonderful reasoner. It is also a great modifier of events. Darwin was prevented for twenty years in promulgating his great thesis; some of the most marvelous inventions took years to bring out and develop into such a state as to make them acceptable to the world. Delays, patiently borne, make strong men. The impetuous think they represent wasted opportunities. Davy Crockett enunciated one of the greatest principles of human action when he said, 'Be sure you are right, then go ahead.' It was only another way of advising against recklessness or impatience in any enterprise."

Thus three days pa.s.sed, and not without misgivings, the signal was given for the start. Angel accompanied them, and with a new flag which the days of leisure had given them an opportunity to prepare, the little craft sailed down the waters of Cataract, in a shining sun, bound for a haven which might mean rest, or to a sh.o.r.e which might offer no welcome to them. The wind was coming mildly from the north, and when they had cleared the sh.o.r.e line and were beyond the influence of the swells, their course was directed to the west. Several miles beyond was a point which projected out to sea; they could see this plainly from Observation Hill, and during the last long trip inland they reached the sea beyond this cape.

The sh.o.r.e line beyond was absolutely unknown to them, but it extended to the west as far as they could see, and when night set in the faint mist prevented them from judging how much farther it ran in that direction.

Without proper instruments at sea, distance is always a difficult matter to judge, and the boys were constantly venturing guesses as to the distance traveled. The start was made shortly after nine o'clock, and it was now past six in the evening.

"How far do you think we have gone during the day?" was George's question.

The Professor made a mental calculation before replying. "If we have traveled at the same speed during the entire course that we made during the first three miles to the cape, we have gone about thirty miles."

"Do you know it is three miles to the cape?"

"Yes, it is approximately that distance. I measured it by triangulation some time ago, using our house and Observation Hill as the base line."

The boys had neglected to take this precaution.

"What was your object in doing that?"

"So that we might have some means to observe the speed our boat could make. If we knew the speed of the wind, we might be able to calculate our distance."

"But the wind has been coming from the north and we are sailing due west. Would not the difference in the speed of the wind make a difference in the speed of the boat?"

"It was for that reason I stated if our rate of travel was the same we would have made that distance. The wind has been variable at different points along the coast, so that our average may have been four miles per hour."

"At what speed has the wind been during the day; I mean the average speed?"

"Less than eight miles an hour?"

"If the wind had been coming from the east we could have made much better time, and we might then have been near the mouth of the West River," was Harry's conclusion.

"Why do you think we should have made better time?" asked the Professor.

"Because we should then have been going with the wind."

"You are entirely wrong in your a.s.sumption. Sailing ships travel faster when tacking than when sailing with the wind."

The boys looked at the Professor in astonishment.

"It does not seem possible," replied George, "that any movement of the wind pushing sidewise could be more effective than a pressure straight ahead. Can you explain the reason for the statement?"

"When the wind blows straight against a sail, certain eddies are produced which cause a convolute stream around its edges. These currents are counter to the forward movement of the vessel. a.s.suming that this normal pressure of the wind is 1,000 pounds, it is estimated that fully half is lost in effectiveness. On the other hand, if the ship is moving forward at right angles to the direction of the wind, and the sail is set at forty-five degrees, that is what is called a tack; while it has only about six-sevenths the surface that it had when going with the wind, the sail is constantly going into new wind and, therefore, the pressure is a constant one and most efficiently applied to the surface."

"Do you mean by this that if I hold up a sail so that the wind blows flat against it, the pressure will not be as great as if I held it at an angle?"

[Ill.u.s.tration: _Fig. 21. Fig. 22. ILl.u.s.tRATING WIND PRESSURE_]

"No; I had reference to a moving object. I can better explain the phenomenon by ill.u.s.trating the two conditions: In the drawing (Fig. 21), let A represent a sail with 100 square feet of surface. The darts (1) represent the wind blowing dead against it. This is called the normal position. You will see the darts representing the direction of the movement of the wind. Now look at the next sketch (Fig. 22). Here the sail (B) is put at an angle of forty-five degrees from the direction of the wind. The sail is still the same size vertically, but it is somewhat smaller horizontally across the line (C), this diminution in size being about one-seventh of the entire area. The darts (D) in both cases represent the movement of the boat, and the darts (2) in the last sketch show the wind striking the sail at an angle."

"In the first sketch the darts (1) strike the sail normally, as you say, in what way do the darts (2) in the next figure strike the sail?"