All the measurements were made on the plan outlined, and scratched on the sooted slab.
"One thing more we must observe. As we are marking the successive points, you will notice that I took particular care to observe the side walls of the passageway, so that I could roughly outline them, noting the distances from the various points, and in a crude way marking out the irregularities between the points."
The chart interested the boys so intensely that the disappearance of the light did not again recur to them until they emerged from the mouth of the cave, when it all came back again, with added wonder and speculation. How many more mysterious things would present themselves!
They returned to their home with conflicting emotions. It had been an eventful day. They had a glimpse of the outside world, and an experience below the surface of the earth. Both were unsatisfying. They could explain the one far away on the sea; but the other, close at hand, was a mystery.
"How do you account for the water being so far away from the mouth of the cave?" was George's inquiry after the evening meal.
"Haven't you noticed that we have had no rain for the past five weeks?"
Such was, indeed, the case. The boys had not been observant, like the Professor.
"Evidently the water is supplied from rains, and the floor of the cave permits more or less of the water to leak through, so that, in time, if we had no rains, the cave would be entirely free of water."
"But how about the animal in there; if it is a water animal, how did it get in; and if the water ever dries up, how can it live there?"
"There may not be any subterranean connection directly with the sea, and the animal has been trapped there; or it may be able to reach the sea in the cave at any time, by some underground channel."
"How far do you think the cave goes in?"
"That is one of the impossible things to say. It may extend for miles. Like yourselves, I am curious to know all about it, as soon as we can make further investigations. In the meantime, don't forget about the flag."
"I had forgotten that. I am willing to start on it in the morning. How large should it be made?"
"We should make it a regulation flag, by all means."
"Let me see; how many stripes must we have?" said Harry.
"I know; thirteen."
"Yes; and they must be red and white."
"That is correct," responded the Professor; "but do you remember how many of each?"
The boys were silent.
"The top and the bottom stripes are red, and the intervening ones white. What do these stripes represent?"
"The original States."
"I see you have a pretty good recollection. I remember a class of over forty boys, on one occasion, which had only three boys who recalled that. Then we must have a field of another color, up in the corner."
"That is the blue field, with stars on it."
"Yes; but how many stars?"
"A star for each State."
"And how many States are there now?"
There was no response to this. How many boys or men, even, can tell offhand the number at the present time?
"There were 48 before we sailed. How many, if any, were added since I do not know."
The next day the boys were anxious to set to work on the flag. There was plenty of the ramie cloth at hand, but it was quite yellow. George noticed this, and said: "It seems to me we shall have to be content with making the flag red, yellow and blue, that is, if we can get the red and the blue."
"No," was the Professor's rejoinder; "we must make it red, white and blue."
"But how can we make the ramie cloth white?"
"By bleaching it."
That was a new idea; to make white cloth.
"How can we do it?"
"Wet it and put it in the sun. If we want to hurry it up we can use some chloride of lime."
"But where is the chloride of lime?"
"Do you remember that black ore we have in the laboratory, which is called manganese? If we put some of the sulphuric acid on that a gas will be formed, called chlorine, one of the most powerful bleaching compounds known. We can use it in that form, or subject some of our lime to the gases, and in that case make chloride of lime."
The decision was to make the flag sixteen feet long and nine feet nine inches wide, so that each stripe would be nine inches wide. The blue field would be five feet wide and seven feet long.
This was certainly a task, and the boys were directed to prepare four strips of red and three strips of white, each nine feet long, and also three strips of white and three strips of red sixteen feet long. Four of the short strips and three of the long strips were then laid aside to be dyed red. The other strips were put out to bleach.
When all this was prepared George was troubled about the colors.
"Professor, I do not see what we can use to make the blue and red colors."
"I think we are fortunate in having one of the varieties of the madder plant all about here."
"Is that a good dye plant?"
"It is a plant that is more extensively used for dyeing than any other in the world. For many years, until the products from petroleum began to come in, it was the only source for the red colors, because of its permanence. The dye is so powerful that it will turn the bones of animals red, if they are fed on it, and it also colors the claws and beaks of birds."
"Have you seen any of it here?"
"There is plenty of it growing here. You cannot mistake it. It is the plant with the elongated, smooth-edged leaf, which grows on the main stem, from which the small, thin stems branch out that carry the little red flowers."
"I know what you mean; let me get some of them at once." And George was off after the plant.
Meanwhile Harry was busily at work cutting out the double set of stars required for the blue field.
Several days before this George had prepared the roots of the chicory plant, as will be remembered, and it had been dried, and was ready to be ground up. At the noon meal he served the first cup of "coffee," to the delight of Harry, who was completely taken by surprise, and afforded much amusement for George and the Professor.
"It seems to be rather strong," was Harry's only comment, "and even if it isn't real coffee, it is good enough, I assure you."
"Wouldn't it be injurious to take too much of it?"
"Exactly with this as with everything else. It is not the use, but the abuse, that causes trouble. Of course, chicory does not have the soothing and hunger-staying qualities of the real coffee, but the bitter principle in the root is a tonic, and the extract is used as a medicine for that purpose. The leaves of the endive, of which we are using the roots, make a most delicious salad."
"Don't many people use this as a kind of an intoxicant?"
"If used to excess it has an exhilarating influence, on account of its tonic properties."
"I have often thought it was wonderful," said Harry, "that people all over the world have some kind of a weed or plant that they use to stimulate themselves with."
"There seems to be a universal instinct in man to select the strong and bitter principles for that purpose. The aborigines of Central America used rolled tobacco leaves ages before Columbus was born; and the coca leaf, chewed by the lowest orders of the Peruvians, was for ages, and is now, their main source of strength and comfort. So opium, hemp and the betel-nut have been used by eastern Asiatics from the remotest antiquity; and the same is true of the pepper plants of the South Sea Islands and the Indian Archipelago; also of the thorn apples used among the natives of the Andes, and on the slopes of the Himalayas. In northern Europe the ledum and the hop have been so used, and in Siberia the narcotic fungus has been eaten from time immemorial."
At that moment Baby appeared on the scene, his hands and one side of his head dyed a beautiful red, presenting a ludicrous appearance. The first glance at him was one of astonishment; but realizing that he had been testing George's newly made dye, all burst out in laughter at the amusing sight.
"You really look like a red angel," was George's greeting, and Baby seemed to relish the joke. From that time forward Baby's name was "Red Angel," but it took him some time to learn what the new title was. It took him much longer to acquire it than it did to learn what honey meant.
"Red Angel is certainly a very smart little chap," said the Professor, with a laugh, "because he was really doing what is done in the dyeing art and in chemistry every day, furnishing a test sample."
"Test sample; what is that?"
"In the art of dyeing it is the custom, before commencing to dye goods, to make a test sample, and all goods dyed must come up to the standard set by that sample. That is called the 'test sample.'"
"But how do the chemists use it?"
"In the analyses of chemicals one of the processes is by what is called the color metric test—that is, the test by color. The chemist makes a solution with a known quantity of the element in it which is of full strength and purity, and is therefore of a well-defined color. Now, if any substance is to be analyzed, the same reagent is used in the tested sample as was used to make the well-known sample. The color of the unknown sample is then compared with the known sample, and the quantity determined by the difference of color in the two."
"What do you mean by reagent?"
"A substance used to effect a chemical change in another substance. For instance, what is called Nessler's Reagent is a substance which, if put into water, will detect one part of ammonia in twenty million parts of water, and give a perceptible reddish-yellow tinge."
"Well, Red Angel has certainly made a good test sample for us; isn't that a good color?"
The blue color was still wanting when the other parts were ready, and the Professor came to the laboratory with a sample of bitter-sweet, the common hedge plant of North America. The boys both recognized the plant and were surprised to learn that it contained a dye suitable for their purpose.
"We can use this or take some of the copper ore, that is, the blue vitriol part of the ore, and by putting it in a lime-water solution a beautiful blue color can be obtained."
The flag, when completed, was really a work of art. They gave many days to the task, and were proud of it. The question of a suitable pole or flagstaff was one which now absorbed their energies. As nothing of the kind was found in the immediate neighborhood, it was suggested that on their regular hunting day it should be made a part of their duty to find a staff worthy to be installed. The trips to the cave, and the absorbing work of preparing the flag, had so taken up the time, that they had entirely forgotten the regular outings.
On this occasion they insisted that the Professor should accompany them, and George declared that the only place available for a good pole would be in the forest below the South River, where they had shot the ocelots.
The yaks were prepared, as usual, and it was a merry party which started off on that bright morning for the forest. They did not, you may be sure, forget the spears and the guns, and before leaving home Harry thought it would be a good idea to provide a small two-wheeled truck, which could be used as a trailer, for the pole.
On the way down, Harry said: "How large a pole shall we get?"
George had his opinions, as usual: "Let us get a pole at least 50 feet long. We must have something which will match the flag."
"A pole that length will be a difficult matter to raise; have you thought of that?" was the Professor's observation.
"Can't we rig up something to raise it with?"
"Yes; and for a pole a hundred feet long, if necessary."
The Professor made no further objections. Reaching the South River the yaks were tethered, and taking advantage of the raft which they had used on the first trip, they were soon on the way into the forest. On this occasion they took a course to the right of their former exploits, the desire being to acquaint themselves, as much as possible, with the topography of the country toward the falls. Soon they came within sight of game, squirrels, woodchucks; and many familiar varieties of birds were seen on all sides.
What interested the boys most was an animal about three and a half feet long, and almost three feet high, which they saw at a distance.
"What is that, Professor?"
"It is a giant ant-eater, found in many parts of South America."
"What a big bushy tail he has."
"He uses that in a peculiar way. When he sleeps he lies on one side, rolls himself up so that his snout lies on his breast, places all his feet together, and covers himself with that bushy tail. As the hair of the tail resembles hay, or the surrounding dried grass, it is likely to be passed by without being noticed."
"I wish we could get a shot at him."
"There is a fine pole," said Harry, whose keen interest was as great in that quarter as in the hunting.
It was an exceptionally fine specimen of shell-bark hickory, and the base was nearly six inches in diameter, but it was as straight as a line, apparently, and it was fully thirty feet to the first limb.
"You couldn't get a better pole; but hickory is one of the heaviest woods, and being green, it will be a task to raise it. It weighs, dry, about 45 pounds per cubic foot."
"What is the weight of a cubic foot of water?"
"About sixty-four pounds."
"How much do you think that pole will weigh when it is trimmed up?"
The Professor, after carefully surveying the tree for a time, answered: "It will weigh fully 400 pounds, but I am in favor of taking it, as we know shell bark is a good American tree, and it is the kind of wood we usually select on account of its strength. I know it will resist any winds likely to come our way."
It was at once cut down, and on measuring was found to be 58 feet up to the branching top, at which point it was not less than two inches in diameter.
"Cut it off above the last crotch, as we shall want that part to attach the top pulley between."
Now that it was cut and trimmed, the problem was to convey it back to the river.
"Do you think we can induce the yaks to swim across the river?"
"That's a capital idea, Harry, let us go back and try it."
"While you are getting the animals I shall do some investigating," said the Professor.
The boys crossed the river and took the two-wheeled truck across. "It might be amusing to the Professor, if he found we had taken the truck across before we knew whether the yaks could be induced to go over." Harry laughed at George, and answered: "How shall we manage it? We had better keep them yoked, I suppose."
After some urging, they were driven to the water, the boys having tied a rope to the yoke before they went into the river. To their great surprise and relief, the yaks made no objections, and immediately started out at a great rate for the opposite shore, and before they had gone twenty feet were swimming. The boys in the raft held on tightly and were drawn across without further trouble.
As they left the river for the trip, they distinctly heard a shot.
"I wonder what the Professor has shot? Did you hear him?" They listened intently. The shot appeared to come from a point considerably to the left of the place where the pole had been cut, but they paid little attention to that. After they had gone halfway another shot was heard, this time at a point which indicated that the Professor must be some distance away.
As anticipated, the Professor was not in the location of the pole.
"I don't think the Professor expected us back so soon," was Harry's suggestion. "Let us rig up the pole and hitch the team, and by that time he may be back."
In less than a half hour this was done, ready for a start; still no signs of the Professor.
"I think we had better fire a shot to let him know we are here."
"Singular we didn't think of that before; here goes." Waiting fully a quarter of an hour after the shot, they were surprised at not hearing any response from him. "I wonder," continued Harry, "if he has met with some accident?"
"We heard it in this direction, didn't we? Don't let us waste any more time. Get the guns and ammunition. Hurry up; and let us take a spear; it may be useful."
Each boy took a spear, as a matter of precaution, and set out. At intervals the boys shouted, and after wandering about for fully a half hour, determined to try another shot. This was answered by a shot apparently from the direction of the team, and the boys turned about and hurriedly made their way back.
It happened that the boys had actually lost their way, and in the excitement all sense of direction. The Professor had made a complete circle and the boys in their wanderings had executed a complete loop within that circle, and were actually going back to the river instead of to the team.
"I can't understand this business," said George, in a despairing tone. "We have traveled far enough to get back to the team twice over. Let's try another shot." It was answered by a shout from the Professor, close by, to their left, and when they appeared in sight he was seated on the log leisurely driving the yaks, laughing in a quiet way, and apparently not noticing the discomfiture of the boys.
"We thought you were lost," said George; "didn't you hear us firing?"
"How does it happen you are going in this direction?" was the Professor's quizzical remark, which he uttered with a faint suspicion of a smile. As the boys did not reply, he continued: "Did you expect to find the team at the river?"
Of course, they all had a good laugh at this, because the direction they were taking, and the position in which the Professor found them, were sufficient to indicate that they were really lost, and that he knew it.
"I felt satisfied," was his final remark, "that you had not a well-defined idea of your direction when you fired the last time, but you will learn in time how to keep your direction, and what is more, you will never again permit an excited condition of the mind to make you take a crooked path."
The boys looked wonderingly at the Professor.
"How," asked Harry, "does an excited mind make anyone take a crooked path?"
"When the mind is excited, it is, for the time, deranged, like soldiers, frequently on the field of battle, who are wounded, without having the least knowledge of it. The sense of direction is a well-developed trait in some people; in others, it does not exist at all. But in the case of either, the moment the mind is excited, it becomes abnormal; some lose the ability to judge distances, some are unable to talk, and others can't do anything but talk. All judgment for the time disappears. Now, take that person in a forest, and highly excite him, and he has absolutely no judgment of distance or direction, and is not in a good position to mark and follow a course with intelligence. I have spoken thus fully on the subject, in order to warn you, that under no circumstances should you ever set out on such a mission as you have with the least cloud of excitement. It is far better not to go at all."
It was a warning the boys never forgot.
On the return home that evening they were surprised to find Red Angel absent. Frequently he would go with them on their trips, but he was purposely left at home on this occasion. He had ample opportunity to roam at will during their absence, and had never strayed away.
"It is very singular he cannot be found. I searched the house, the shop, and the cattle range, and he is nowhere in sight."
It was a grief to all to miss him, as all had learned to appreciate his mischievous tricks, and George had taken a delight in "educating" him. Probably now, that he had grown to a more mature age, the spirit of the wild life possessed him, and he had taken French leave at the first opportunity.
George missed him more than Harry, because as cooking was one of George's accomplishments, and as honey was the weak spot in Red Angel, the kitchen was an attraction, and the reward for service in the kitchen was this delicious sweet.
Their stock of this was running low. George was not as liberal with honey of late, and after ruminating on the subject of the disappearance, he concluded that Red Angel had cause for "running away."
The next morning while at breakfast, who should appear at the door but Red Angel, his long fingers and palms holding a quantity of nuts. He evidently saw that the welcome was most enthusiastic on the part of all. With the utmost gravity he shambled across the floor and deposited the nuts on the table and took his usual place in the most matter-of-fact way, and commenced on the nuts as though it was part of a solemn duty.
George's hand reached out for the honey; Angel saw it, a quizzical look came on his face—a real orang smile—and he forgot about the nuts.
In a spirit of fun George helped himself without offering any. This was too much for the animal, and with a shrewd, calculating look he pushed the nuts over to George.
Did he get any honey after this? George could not resist this appeal; and after Angel got it, and George helped himself to nuts, the Simian approval was very marked. Do you think he reasoned?
Preparations must now be made for "pole-raising day." In the absence of a sufficient amount of rope the last bearskin was cut up into strips, as it was necessary to have nearly a hundred feet, and the bearskin was a much-needed addition to the small quantity of ramie cord which they had on hand.
The Professor took a keen interest in the proceedings. "We must get a half dozen forked poles of good wood; they should be of different lengths, to support the pole as it goes up. Then, Harry, as we have a pretty tough job before us, I suggest that you make two capstans, something like those you saw on shipboard, around which the two raising ropes can he wound, each to have a crank, and a means for holding the crank at any position."
The preparations occupied the greater part of the day. Several boards, five feet long, were required, and at least a dozen stakes to hold the capstans in position.
Early the following morning the yaks were brought out, yoked up, and the pole and truck hitched on. A luncheon was provided, the flag and all paraphernalia assembled and loaded, and Red Angel invited to attend the ceremonies.
Reaching Observation Hill, a spot for the pole was selected, and a hole three feet in diameter and five feet deep was laboriously dug out. It was, indeed, a trying task, with the tools they had, but it was a labor of love. It was more than that to them. They were now making preparations to notify the world that they still lived.
The top of the pole had been provided with a pulley, which was mounted between the crotch, and a guard put over the pulley, so it would prevent the halliards from coming off. When it had been placed in position, with the foot across the hole, the two boards were stood down in the pit so the end of the pole was against them. The halliards were then strung over the pulley and looped down, and the three ropes were attached to the pole, twenty feet from the lower end. Together they raised it up, so that it was about five feet from the ground at the point where the ropes were tied. Two of the ropes were then carried out past the hole, and branched out, and attached to the capstans, while the other was allowed to hang. As the capstans turned, the pole was gradually drawn up, and the Professor stood ready with the forked standards to prevent the flagstaff from falling back. In less than an hour it was erect, and the work of tamping in the dirt and stone around the base was in order, and soon completed.
And now for the flag!
"Tell us, Professor, why the attaching of the flag on the cord, or halliards, is called bending it?"
"The term comes from heraldry, and it originally designated two diagonal lines across the field of an escutcheon. Later on, sailors bent the ends of the flags or ensigns on the halliards, or around the yards, and also called the fastening of a cable to the anchor a bend; a knot is also designated by them as a bend; the form of the ship from the keel to the top of the side is called a bend, as, the midship bend."
A strong rope had been seamed in the end of the flag, and eyelets worked at intervals, so that the task of attaching it to the halliards was soon performed.
"The raising of the national emblem for the first time in any new country has always been regarded as an event of the greatest importance, as it represents sovereignty and responsibility. On this occasion," said the Professor, as he removed his hat, "let us honor the flag with appropriate ceremonies."
At that moment Red Angel concluded he would also take part, and in an instant was at the pole and scrambled upwardly. When the top was reached he caught sight of the wheel. It moved. Every time he grasped the rope the wheel would turn.
This seriously interrupted the program. The Professor could not help laughing. A moment before he was particularly grave, and the boys had no feelings of mirth; but now this new element in the proceedings added gaiety to the occasion.
"Come down, you rascal! Come down! Do you hear me?" cried George. Red Angel didn't hear. He hung there and smiled; yes, smiled, as he looked down, while playing with the wheel. "We can't put up the flag while he is there." George walked over to the wagon, and took out the honey pot. Red Angel saw it, but made no motion to come down. The honey pot was held up as an inducement, but there was nothing in the world so fascinating just then as that wheel.
Harry and the Professor laughed at the situation. Just to think of it! An orang-outan actually preventing a foreign power from hoisting the emblem of possession over his native land! It was too ludicrous for words.
George actually became almost hysterical as he threw himself back on the seat of the wagon and held up the honey pot, while laughing. "What do you think that little scamp has been doing? He has eaten every bit of the honey." That only added another fit of laughter, and when it subsided, and George could recover his voice, he added, "and wasn't this a smart thing to do?" as he held up the vessel.
"What?" asked Harry, momentarily straightening out his face.
"He actually put the lid back after he got through."
But this could not last indefinitely. No one suggested a remedy, if there was one. The United States must take possession in the proper way; hats must come off; the flag must go up slowly, and the band must play the national air;—the music, they had not thought of it before.
"Can you climb the pole, George?" asked the Professor.
"I think so, with the aid of the halliard."
He approached the pole. "Do you hear me, Baby, come down! Come down, I say!"
Red Angel saw George's design, and without saying a word he slowly descended, shambled over to the wagon, and hanging on the side of the box, looked around to the company in the most reproachful manner.
The hoisting of the flag was, indeed, a solemn thing, but it had its amusing side, and when, with uncovered heads, the flag went up to the masthead and stopped there, the Professor said: "We should have had music to make it more appropriate, but as we have no band, let us sing 'The Star-Spangled Banner.'"
The boys were both good singers, as the Professor knew. The song was started, but before the first line was finished, they broke down and tears began to come; the Professor, with his hands clasped and head bowed, did not look up, nor was he surprised when they stopped. The boys had a suspicion that even he could not have carried that song a single bar. They were powerless to go on.
When the Professor did look up and gaze on the flag, the boys saw his tears; they were ashamed no longer, and their eyes looked up, too.
In a voice which sounded almost strange to the boys, the Professor said: "We take possession of this land in the name of the United States of America, and give notice that we shall defend the same against all powers."
Then, as the beautiful flag unfurled itself, and threw its waving shadow on the ground that it now protected, they looked down, and there was Red Angel, close beside them, looking up at the flag as though he understood what it meant, and his silence gave consent to the solemn act which transferred his allegiance to a greater power.
As they were about to descend the hill the Professor called them to a halt. "Do you intend to leave the flag at full mast?"
They had entirely forgotten to half mast it. "And now," said Harry, "if they can't see that flag we'll make one big enough next time."
As they went down the hill, they could not help looking back over and over, to admire the flag and the pole, and everything connected with it. They knew every thread and every piece of it. Somehow it seemed to be a part of them.
There was always a sentimental streak in George. "I can't help thinking that is the most beautiful flag in the world; I suppose other people think the same of their flag. How did flags come to be used by people?"
"The flag is the successor of the banner, which is taken from the Celtic word 'band.' The Bible mentions banners, showing they were used early in scriptural history. The banners of the Romans, used in their warfares, were essentially different from modern flags, colors and ensigns; they were carvings of wood or metal, some of them representing eagles, like the Persian standard described by Xenophon. In the Middle Ages it was a connecting link between the military and the clergy. The crescent and the cross symbols typified the two great contending forces of the world at that time."
Returning to their home, tired with the exertions, they sat in the living room and talked over the events of the day. Somehow, they felt that the day was too sacred to be desecrated with further toil. They congratulated each other at the success in raising the pole, as that was a matter which had given them a great deal of concern.
Ever since the day on which they commenced work on the electric battery the boys deplored the lack of glass. If they could make that it would be of such immense importance to them in many ways. It would be of great service for their tableware; they could use it for their electric work, which interested them more than any branch to which their time had been given, among the mechanical arts; with that they could make thermometers and testing instruments; and give their house the air of a modern home, because windows could be put in.
"Will it be difficult to make glass?" asked George.
"It is an exceedingly simple matter to make glass—that is, to fuse or melt it. The difficult part is the art of making it, either by the blowing process, or by making the flat forms, like window panes and the like. Owing to the simplicity in preparing it, the making of glass articles was known at a very early date, certainly fifteen hundred years before the beginning of the Christian era. In the first stages only opaque glass was produced, and it was not until eight hundred years later that the first transparent product was manufactured. Under Pharaoh it was one of the products extensively made and exported to Phonecia and other Mediterranean ports. Five hundred years before Christ, Aristophanes mentions glass or crystal vessels, but as its value at that time was next to gold it could not have been a common article."
"What is glass made of?"
"Simply common sand. Sand is the ground up particles of quartz, and may be found almost everywhere. The principal thing is to get the pure quartz. In connection an alkali of some kind must be used."
"What is an alkali?"
"A substance which is the exact opposite of an acid. Potash, soda and hartshorn (or ammonia) are the best known. They have most remarkable chemical activities, and an alkali united with an acid entirely neutralizes or destroys the activity of both. The compound produced by the union of an acid and an alkali is termed a salt."
"What is the effect of using an alkali with the quartz sand?"
"Quartz possesses all the qualities of an acid, so that when the alkali is fused with the quartz a neutral substance, unlike either, is formed."
"What kind of alkali is best to use?"
"That depends on what it is to be used for. Quartz and lime make a fine window glass product. Bottle glass is usually made of soda and quartz; window glass is also made of quartz, soda and lime; plate glass of quartz, lime, soda and potash; and flint glass has only the alkalis, potash and oxide of lead."
"Well, for our purposes, wouldn't it be better to make the glass out of quartz and lime if windows can be made out of it?"
"By all means, for several reasons: We have the lime on hand, and also because it makes a very hard article."
"What can we melt it up in?"
"The clay retort or crucible will just be the thing for the purpose, and the first thing in the morning I will make a tour to a point close at hand, where I think we shall be able to get a good quality."
The boys were astir in the morning earlier than usual. They had a new impulse—something to learn and to do. Harry busied himself with putting the crucible in order, and in getting the fuel. George, after his usual morning's work, brought in the lime, and broke it up preparatory to grinding it up into small particles, so that it would intimately mix with the sand.
Within an hour the Professor returned with several samples of sand, either of which, he thought, would make a good article. The yaks were hitched up, and George went with him to get a good supply.
"How much do you think we ought to make up at first?"
"Several gallons of the sand will do for the experiment."
"What kind of article should be made with the first trial?"
"We might make some window glass. It is true it will not be transparent, but it will be translucent, and so will give us light, as well as though it should be transparent."
"What is translucent glass?"
"Where the surface of a cast plate is polished the material is such that you can see through it, but if it is left rough it is impossible to see through it, although it will permit light to go through. The term applied to such glass is translucent."
"If light will pass through, why is it the eye cannot see through it?"
"A powerful magnifying glass shows that the surface of unpolished glass is formed by a layer of crystals, or of sand, with the faces projecting out in all directions and at all angles. The result is, that a beam of light from the eye strikes one or more of these faces and is diverted from a straight line through the glass. As all the rays are thus changed from a direct course, confusion results, and the eye distinguishes nothing."
Several bushels of the sand were brought to the laboratory, and the Professor then directed the preparation of a half dozen slate slabs, each slab being nearly two feet square. He explained that in practice iron plates were used, but as they had nothing of that kind available, slate would answer admirably.
"The slate slabs must be heated, and when the fused material is poured on the slabs, the heat must be kept up for a short time and gradually cooled down."
"What is the object in doing that?"
"If cooled too suddenly the plates, will crack, but by heating the slates and then cooling them down gradually, we anneal the glass, in a measure. You remember how we annealed the steel by gradually cooling it down? Glass, however, cannot be annealed so that it will not fracture, although attempts have been made for years to find a means for doing it. The man who can discover a process that will enable it to bend without breaking, can command any price for the discovery."
The Professor supervised every part of the operation with the utmost care. "Before the plates are heated you must put a raised margin around each slate square, so the molten material will not run off."
"How high shall we make the margins?"
"About a quarter inch above the surface of the slate."
"As we are now ready to heat up the crucible, how shall the materials be mixed?"
"For this trial, measure out eight quarts of sand and two quarts of the lime, and after depositing it in the crucible, we are ready for the heat."
In a short time, with the assistance of the blower, which has already been described, the sand began to melt. It was now stirred so that the elements were thoroughly mingled. During the melting period the dross or impurities which came to the top were skimmed off, and when no more of the impurities collected the Professor stated that they might remove the crucible and pour the melted mass into small pockets, which they had previously formed with clay.
"Why not pour this on the slate forms we made?"
"Because we must know that we have a good sample of glass, and for the further reason that the product we are now to make should have some glass in it that has already been fluxed before, and we now have such a manufactured material."
The material which had been cast in the pockets was broken up with a hammer, as soon as it had cooled, and its appearance noted.
"I see we shall have to use less lime."
"Why?"
"You will note that it is too white or milky-like. This shows too much lime and consequently it is very brittle."
"Suppose, on the other hand, there was too little lime, what would be the result?"
"We should then have a glass which would not hang together at all. In the one case, as with the present sample, with too much lime in it, we have made a product which is closely allied to the alkaline base; and if we had, on the other hand, too little lime, we should have something which is nearly like quartz, hence not suitable for our purpose."
"It seems, then, we have to do in this case just as Red Angel did, make a test sample?"
This allusion to their pet caused a smile all around.
Since the trip made by our colonists two months before they made no effort to gain any additional knowledge of their island. What they really knew of the country, aside from two of the trips made in the interior, under very unfavorable circumstances, was of no value as a means of locating the natives.
That the island was inhabited there could no longer be any reason to doubt. The fire plot on the banks of the Cataract River, the lights near the woods beyond the West River, the finding of the arrows, and the mysterious use of the boat which had so strangely disappeared from the falls in South River, to say nothing of the removal of the flag and flagstaff, were evidences which could not be disregarded.
The further investigations which they must make for their own safety was one of the impelling steps which determined them to build another boat. The discovery of the wrecked portion of the life-boat and the decision to utilize the recovered portion for the new craft had facilitated their preparations somewhat, but there was still a great deal of work to do.
They had six imperfect guns, as they called them, mere pistols, muzzle-loaders, with barrels eight inches long, and the powder was not the best which could be made. Everything was crude and imperfect, and to boldly venture out among savage tribes with such an equipment would not be wise.
All these things were considered in their conferences. But another matter was suggested by the Professor, which carried some weight. A sail had been seen by them. There could be no question on that point. Other ships might come again, and now that they had a flag of such proportions that it would be seen miles further than the original one, it was possible that the opportunity of rescue might be more likely from their side of the island than anywhere else.
It was certain that if a ship should, in their absence, reach the port, and even discover their home through the instrumentality of the evidence which they had left at the signal flag, there was no assurance that the vessel would await their return, or undertake the mission of rescuing them from the savages, if they should be so unfortunate as to be captured.
It was a most distracting thing to solve. It was not only perplexing, but exceedingly trying, to feel that at any moment a visit might be expected from the natives.
Nevertheless, after all considerations, and giving due weight to the likelihood that some ship might visit them, the building of the boat was decided on, and it was to be of such a character that it could circumnavigate the island. They believed it to be their first duty to do this.
This was the Professor's view: "If we can build a boat large enough, and make it of sufficient strength to carry us and the provisions we must take with us, on such a voyage, we should, at some point in our tour, find the natives, and determine their character."
"But, supposing, Professor, that they discover our boat and should pursue us?"
"My reply to that is, that our vessel must be made of sufficient size and strength to outsail them. My opinion is that the most they have is canoes, and we could readily cope with them. The difficulty is this: If we should be discovered, their curiosity, to say the least, would be sufficient to cause them to trail us along the shore, and it would be exceedingly uncomfortable to have them follow us around the shores to our home. Afloat, in strange localities, on an uncharted sea, at night, is a trying situation with a sailor, even though he has all the instruments of navigation at his command. To go ashore, under the circumstances, knowing that the savages are in wait, would be fully as dangerous."
To Harry's practical turn of mind, there was another feature that might be considered. "Some time ago you stated, Professor, that it was quite possible we had an island near us as a neighbor, and from which we may have had visitors. If such is likely to be the case, our boat will be the means of enabling us to reach that island, because if they have boats of sufficient size to come here they will be civilized, at any rate."
It will thus be seen from a consideration of all the conditions what determined them to increase the dimensions of the proposed new boat, although it would consume more time than they had originally contemplated.
"Do you remember, boys, that it is now about one year since we left the harbor of New York on our voyage in the training ship Investigator?"
"Yes, and we have been on this island for nine months," answered George. "I can hardly believe it possible."
What might be called spring was now at hand, and as the warm rains had quickened the vegetation, the Professor suggested that it would be prudent to devote some time to the planting of such crops as could be utilized by them. Barley was a crop which grew in sufficient quantities all about them, so that no care need be taken in that direction.
Garden vegetables would be needed most. Wild potatoes grew in many places, but when they were needed search had to be made. Endives, which made excellent greens, could also be found, together with the cassava, and a variety of peas; but aside from the foregoing, nothing else was available.
While talking on this subject one day the Professor remarked: "In my wanderings I found quite a variety of plants that we might utilize in our proposed garden or farm. One of them is a small, triangularly formed, dark brown seed, which you may recognize."
"That," was Harry's answer, "looks something like our buckwheat."
"You are right; I found several varieties; none of them exactly like the kind grown in the States, but we can readily propagate it, so that it will be practically the same."
"How is the propagation done, so as to bring about the change?"
"It is merely a careful selection of the best varieties of the particular plant, and by budding, grafting, or inarching, transmitting the qualities of the good kind to the stalk or tree which bears the inferior kind. That is done with vegetation which is perennial, like fruit trees and the like."